diff --git a/lib/obp60task/OBPDataOperations.cpp b/lib/obp60task/OBPDataOperations.cpp
index daca553..cc6ac2a 100644
--- a/lib/obp60task/OBPDataOperations.cpp
+++ b/lib/obp60task/OBPDataOperations.cpp
@@ -1,45 +1,51 @@
 #include "OBPDataOperations.h"
 
-void WindUtils::to2PI(double* a)
+double WindUtils::to2PI(double a)
 {
-    while (*a < 0) {
-        *a += 2 * M_PI;
+    a = fmod(a, 2 * M_PI);
+    if (a < 0.0) {
+        a += 2 * M_PI;
     }
-    *a = fmod(*a, 2 * M_PI);
+    return a;
 }
 
-void WindUtils::toPI(double* a)
+double WindUtils::toPI(double a)
 {
-    *a += M_PI;
-    to2PI(a);
-    *a -= M_PI;
+    a += M_PI;
+    a = to2PI(a);
+    a -= M_PI;
+
+    return a;
 }
 
-void WindUtils::to360(double* a)
+double WindUtils::to360(double a)
 {
-    while (*a < 0) {
-        *a += 360;
+    a = fmod(a, 360);
+    if (a < 0.0) {
+        a += 360;
     }
-    *a = fmod(*a, 360);
+    return a;
 }
 
-void WindUtils::to180(double* a)
+double WindUtils::to180(double a)
 {
-    *a += 180;
-    to360(a);
-    *a -= 180;
+    a += 180;
+    a = to360(a);
+    a -= 180;
+
+    return a;
 }
 
 void WindUtils::toCart(const double* phi, const double* r, double* x, double* y)
 {
-    *x = *r * sin(radians(*phi));
-    *y = *r * cos(radians(*phi));
+    *x = *r * sin(*phi);
+    *y = *r * cos(*phi);
 }
 
 void WindUtils::toPol(const double* x, const double* y, double* phi, double* r)
 {
-    *phi = 90 - degrees(atan2(*y, *x));
-    to360(phi);
+    *phi = (M_PI / 2) - atan2(*y, *x);
+    *phi = to2PI(*phi);
     *r = sqrt(*x * *x + *y * *y);
 }
 
@@ -57,80 +63,96 @@ void WindUtils::addPolar(const double* phi1, const double* r1,
 
 void WindUtils::calcTwdSA(const double* AWA, const double* AWS,
     const double* CTW, const double* STW, const double* HDT,
-    double* TWD, double* TWS)
+    double* TWD, double* TWS, double* TWA)
 {
-    double AWD = *AWA + *HDT;
+    double awd = *AWA + *HDT;
+    awd = to2PI(awd);
     double stw = -*STW;
-    Serial.println("calcTwdSA: AWA: " + String(*AWA) + ", AWS: " + String(*AWS) + ", CTW: " + String(*CTW) + ", STW: " + String(*STW) + ", HDT: " + String(*HDT));
-    addPolar(&AWD, AWS, CTW, &stw, TWD, TWS);
+    //    Serial.println("\ncalcTwdSA: AWA: " + String(*AWA) + ", AWS: " + String(*AWS) + ", CTW: " + String(*CTW) + ", STW: " + String(*STW) + ", HDT: " + String(*HDT));
+    addPolar(&awd, AWS, CTW, &stw, TWD, TWS);
 
-    // Normalize TWD to 0-360°
-    while (*TWD < 0)
-        *TWD += 360;
-    while (*TWD >= 360)
-        *TWD -= 360;
-
-    Serial.println("calcTwdSA: TWD: " + String(*TWD) + ", TWS: " + String(*TWS));
+    // Normalize TWD and TWA to 0-360°
+    *TWD = to2PI(*TWD);
+    *TWA = toPI(*TWD - *HDT);
+    //    Serial.println("calcTwdSA: TWD: " + String(*TWD) + ", TWS: " + String(*TWS));
 }
 
 bool WindUtils::calcTrueWind(const double* awaVal, const double* awsVal,
-    const double* cogVal, const double* stwVal, const double* hdtVal,
-    const double* hdmVal, double* twdVal, double* twsVal)
+    const double* cogVal, const double* stwVal, const double* sogVal, const double* hdtVal,
+    const double* hdmVal, const double* varVal, double* twdVal, double* twsVal, double* twaVal)
 {
-    double hdt, ctw;
-    double hdmVar = 3.0; // Magnetic declination, can be set from config if needed
-    double twd, tws;
+    double stw, hdt, ctw;
+    double twd, tws, twa;
+    static const double DBL_MIN = std::numeric_limits<double>::lowest();
 
-    if (*hdtVal == __DBL_MIN__) {
-        if (*hdmVal != __DBL_MIN__) {
-            hdt = *hdmVal + hdmVar; // Use corrected HDM if HDT is not available
+    if (*hdtVal != DBL_MIN) {
+        hdt = *hdtVal; // Use HDT if available
+    } else {
+        if (*hdmVal != DBL_MIN && *varVal != DBL_MIN) {
+            hdt = *hdmVal + *varVal; // Use corrected HDM if HDT is not available
+            hdt = to2PI(hdt);
+        } else if (*cogVal != DBL_MIN) {
+            hdt = *cogVal; // Use COG as fallback if HDT and HDM are not available
         } else {
             return false; // Cannot calculate without valid HDT or HDM
         }
     }
-    ctw = *hdtVal + ((*cogVal - *hdtVal) / 2); // Estimate CTW from COG
 
-    if ((*awaVal == __DBL_MIN__) || (*awsVal == __DBL_MIN__) || (*cogVal == __DBL_MIN__) || (*stwVal == __DBL_MIN__)) {
+    if (*cogVal != DBL_MIN) {
+        ctw = *cogVal; // Use COG as CTW if available
+        //    ctw = *cogVal + ((*cogVal - hdt) / 2); // Estimate CTW from COG
+    } else {
+        ctw = hdt; // 2nd approximation for CTW;
+        return false;
+    }
+
+    if (*stwVal != DBL_MIN) {
+        stw = *stwVal; // Use STW if available
+    } else if (*sogVal != DBL_MIN) {
+        stw = *sogVal;
+    } else {
+        // If STW and SOG are not available, we cannot calculate true wind
+        return false;
+    }
+
+    if ((*awaVal == DBL_MIN) || (*awsVal == DBL_MIN) || (*cogVal == DBL_MIN) || (*stwVal == DBL_MIN)) {
         // Cannot calculate true wind without valid AWA, AWS, COG, or STW
         return false;
     } else {
-        calcTwdSA(awaVal, awsVal, cogVal, stwVal, hdtVal, &twd, &tws);
+        calcTwdSA(awaVal, awsVal, &ctw, stwVal, &hdt, &twd, &tws, &twa);
         *twdVal = twd;
         *twsVal = tws;
+        *twaVal = twa;
 
         return true;
     }
 }
 
-/*
-// make function available in Python for testing
-static PyObject* true_wind(PyObject* self, PyObject* args) {
-    double AWA,AWS,CTW,STW,HDT,TWS,TWD;
-    if (!PyArg_ParseTuple(args, "ddddd", &AWA, &AWS, &CTW, &STW, &HDT)) {
-        return NULL;
+void HstryBuf::fillWndBufSimData(tBoatHstryData& hstryBufs)
+// Fill most part of TWD and TWS history buffer with simulated data
+{
+    double value = 20.0;
+    int16_t value2 = 0;
+    for (int i = 0; i < 900; i++) {
+        value += random(-20, 20);
+        value = WindUtils::to360(value);
+        value2 = static_cast<int16_t>(value * DEG_TO_RAD * 1000);
+        hstryBufs.twdHstry->add(value2);
     }
-
-    calc_true_wind(&AWA, &AWS, &CTW, &STW, &HDT, &TWD, &TWS);
-
-    PyObject* twd = PyFloat_FromDouble(TWD);
-    PyObject* tws = PyFloat_FromDouble(TWS);
-    PyObject* tw = PyTuple_Pack(2,twd,tws);
-    return tw;
 }
 
-static PyMethodDef methods[] = {
-    {"true_wind", true_wind, METH_VARARGS, NULL},
-    {NULL, NULL, 0, NULL}
-};
+/* double genTwdSimDat()
+{
+    simTwd += random(-20, 20);
+    if (simTwd < 0.0)
+        simTwd += 360.0;
+    if (simTwd >= 360.0)
+        simTwd -= 360.0;
 
-static struct PyModuleDef module = {
-    PyModuleDef_HEAD_INIT,
-    "truewind",    // Module name
-    NULL,          // Optional docstring
-    -1,
-    methods
-};
+    int16_t z = static_cast<int16_t>(DegToRad(simTwd) * 1000.0);
+    pageData.boatHstry.twdHstry->add(z); // Fill the buffer with some test data
 
-PyMODINIT_FUNC PyInit_truewind(void) {
-    return PyModule_Create(&module);
-}*/
\ No newline at end of file
+    simTws += random(-200, 150) / 10.0; // TWS value in knots
+    simTws = constrain(simTws, 0.0f, 50.0f); // Ensure TWS is between 0 and 50 knots
+    twsValue = simTws;
+}*/
diff --git a/lib/obp60task/OBPDataOperations.h b/lib/obp60task/OBPDataOperations.h
index 2ea8fdc..c9e4386 100644
--- a/lib/obp60task/OBPDataOperations.h
+++ b/lib/obp60task/OBPDataOperations.h
@@ -1,48 +1,36 @@
 #pragma once
-// #include <Python.h>
 #include "GwApi.h"
+#include "OBPRingBuffer.h"
 #include <Arduino.h>
 #include <math.h>
 
-// #define radians(a) (a*0.017453292519943295)
-// #define degrees(a) (a*57.29577951308232)
+typedef struct {
+    RingBuffer<int16_t>* twdHstry;
+    RingBuffer<int16_t>* twsHstry;
+} tBoatHstryData; // Holds pointers to all history buffers for boat data
+
+class HstryBuf {
+
+public:
+    void fillWndBufSimData(tBoatHstryData& hstryBufs); // Fill most part of the TWD and TWS history buffer with simulated data
+};
 
 class WindUtils {
 
 public:
-    static void to360(double* a);
-    static void to180(double* a);
-    static void to2PI(double* a);
-    static void toPI(double* a);
+    static double to2PI(double a);
+    static double toPI(double a);
+    static double to360(double a);
+    static double to180(double a);
     static void toCart(const double* phi, const double* r, double* x, double* y);
     static void toPol(const double* x, const double* y, double* phi, double* r);
     static void addPolar(const double* phi1, const double* r1,
         const double* phi2, const double* r2,
         double* phi, double* r);
-    static bool calcTrueWind(const double* awaVal, const double* awsVal,
-        const double* cogVal, const double* stwVal, const double* hdtVal,
-        const double* hdmVal, double* twdVal, double* twsVal);
     static void calcTwdSA(const double* AWA, const double* AWS,
         const double* CTW, const double* STW, const double* HDT,
-        double* TWD, double* TWS);
-};
-
-/*
-// make function available in Python for testing
-static PyObject* true_wind(PyObject* self, PyObject* args);
-static PyMethodDef methods[] = {
-    {"true_wind", true_wind, METH_VARARGS, NULL},
-    {NULL, NULL, 0, NULL}
-};
-
-static struct PyModuleDef module = {
-    PyModuleDef_HEAD_INIT,
-    "truewind",    // Module name
-    NULL,          // Optional docstring
-    -1,
-    methods
-};
-
-PyMODINIT_FUNC PyInit_truewind(void) {
-    return PyModule_Create(&module);
-} */
\ No newline at end of file
+        double* TWD, double* TWS, double* TWA);
+    static bool calcTrueWind(const double* awaVal, const double* awsVal,
+        const double* cogVal, const double* stwVal, const double* sogVal, const double* hdtVal,
+        const double* hdmVal, const double* varVal, double* twdVal, double* twsVal, double* twaVal);
+};
\ No newline at end of file
diff --git a/lib/obp60task/OBPRingBuffer.h b/lib/obp60task/OBPRingBuffer.h
index 3aba92b..4b5e5bd 100644
--- a/lib/obp60task/OBPRingBuffer.h
+++ b/lib/obp60task/OBPRingBuffer.h
@@ -31,6 +31,7 @@ public:
     RingBuffer(size_t size);
     void setMetaData(String name, String format, int updateFrequency, T minValue, T maxValue); // Set meta data for buffer
     bool getMetaData(String& name, String& format, int& updateFrequency, T& minValue, T& maxValue); // Get meta data of buffer
+    String getName() const; // Get buffer name
     void add(const T& value); // Add a new value to  buffer
     T get(size_t index) const; // Get value at specific position (0-based index from oldest to newest)
     T getFirst() const; // Get the first (oldest) value in buffer
diff --git a/lib/obp60task/OBPRingBuffer.tpp b/lib/obp60task/OBPRingBuffer.tpp
index 4c9580f..a0da425 100644
--- a/lib/obp60task/OBPRingBuffer.tpp
+++ b/lib/obp60task/OBPRingBuffer.tpp
@@ -57,6 +57,13 @@ bool RingBuffer<T>::getMetaData(String& name, String& format, int& updateFrequen
     return true;
 }
 
+// Get buffer name
+template <typename T>
+String RingBuffer<T>::getName() const
+{
+    return dataName;
+}
+
 // Add a new value to buffer
 template <typename T>
 void RingBuffer<T>::add(const T& value)
@@ -129,9 +136,9 @@ T RingBuffer<T>::getMin() const
         return MIN_VAL;
     }
 
-    T minVal = getFirst();
+    T minVal = MAX_VAL;
     T value;
-    for (size_t i = 1; i < count; i++) {
+    for (size_t i = 0; i < count; i++) {
         value = get(i);
         if (value < minVal && value != MIN_VAL) {
             minVal = value;
@@ -150,7 +157,7 @@ T RingBuffer<T>::getMin(size_t amount) const
     if (amount > count)
         amount = count;
 
-    T minVal = getLast();
+    T minVal = MAX_VAL;
     T value;
     for (size_t i = 0; i < amount; i++) {
         value = get(count - 1 - i);
@@ -169,9 +176,9 @@ T RingBuffer<T>::getMax() const
         return MIN_VAL;
     }
 
-    T maxVal = getFirst();
+    T maxVal = MIN_VAL;
     T value;
-    for (size_t i = 1; i < count; i++) {
+    for (size_t i = 0; i < count; i++) {
         value = get(i);
         if (value > maxVal && value != MIN_VAL) {
             maxVal = value;
@@ -190,7 +197,7 @@ T RingBuffer<T>::getMax(size_t amount) const
     if (amount > count)
         amount = count;
 
-    T maxVal = getLast();
+    T maxVal = MIN_VAL;
     T value;
     for (size_t i = 0; i < amount; i++) {
         value = get(count - 1 - i);
@@ -328,7 +335,7 @@ bool RingBuffer<T>::isFull() const
     return is_Full;
 }
 
-// Get lowest possible value for buffer; used for initialized buffer data
+// Get lowest possible value for buffer; used for non-set buffer data
 template <typename T>
 T RingBuffer<T>::getMinVal() const
 {
diff --git a/lib/obp60task/PageWindPlot.cpp b/lib/obp60task/PageWindPlot.cpp
index a07c03c..1a209d1 100644
--- a/lib/obp60task/PageWindPlot.cpp
+++ b/lib/obp60task/PageWindPlot.cpp
@@ -4,20 +4,17 @@
 #include "OBP60Extensions.h"
 #include "OBPRingBuffer.h"
 #include "Pagedata.h"
-#include <N2kMessages.h> // just for RadToDeg function
 #include <vector>
 
 static const double radToDeg = 180.0 / M_PI; // Conversion factor from radians to degrees
-// #define radians(a) (a * 0.017453292519943295)
-// #define degrees(a) (a * 57.29577951308232)
 
 // Get maximum difference of last <amount> of TWD ringbuffer values to center chart
 int getRng(const RingBuffer<int16_t>& windDirHstry, int center, size_t amount)
 {
     int minVal = windDirHstry.getMinVal();
     size_t count = windDirHstry.getCurrentSize();
-//    size_t capacity = windDirHstry.getCapacity();
-//    size_t last = windDirHstry.getLastIdx();
+    //    size_t capacity = windDirHstry.getCapacity();
+    //    size_t last = windDirHstry.getLastIdx();
 
     if (windDirHstry.isEmpty() || amount <= 0) {
         return minVal;
@@ -30,7 +27,7 @@ int getRng(const RingBuffer<int16_t>& windDirHstry, int center, size_t amount)
     int maxRng = minVal;
     // Start from the newest value (last) and go backwards x times
     for (size_t i = 0; i < amount; i++) {
-//        value = windDirHstry.get(((last - i) % capacity + capacity) % capacity);
+        //        value = windDirHstry.get(((last - i) % capacity + capacity) % capacity);
         value = windDirHstry.get(count - 1 - i);
 
         if (value == minVal) {
@@ -49,43 +46,6 @@ int getRng(const RingBuffer<int16_t>& windDirHstry, int center, size_t amount)
     return maxRng;
 }
 
-void fillSimData(PageData& pageData)
-// Fill part of the TWD history buffer with simulated data
-{
-    int value = 20;
-    int16_t value2 = 0;
-    for (int i = 0; i < 900; i++) {
-        value += random(-20, 20);
-        if (value < 0)
-            value += 360;
-        if (value >= 360)
-            value -= 360;
-        value2 = static_cast<int16_t>(DegToRad(value) * 1000.0);
-        pageData.boatHstry.twdHstry->add(value2);
-    }
-}
-
-void fillTstBuffer(PageData& pageData)
-{
-    float value = 0;
-    int value2 = 0;
-    for (int i = 0; i < 60; i++) {
-        pageData.boatHstry.twdHstry->add(-10); // -> irregular data
-    }
-    for (int i = 0; i < 20; i++) {
-        for (int j = 0; j < 20; j++) {
-            value += 10;
-            value2 = static_cast<int>(DegToRad(value) * 1000.0);
-            pageData.boatHstry.twdHstry->add(value2);
-        }
-        for (int j = 0; j < 20; j++) {
-            value -= 10;
-            value2 = static_cast<int>(DegToRad(value) * 1000.0);
-            pageData.boatHstry.twdHstry->add(value2);
-        }
-    }
-}
-
 // ****************************************************************
 class PageWindPlot : public Page {
 
@@ -105,7 +65,7 @@ public:
     virtual void setupKeys()
     {
         Page::setupKeys();
-        commonData->keydata[0].label = "MODE";
+        //        commonData->keydata[0].label = "MODE";
         commonData->keydata[1].label = "INTV";
         commonData->keydata[4].label = "TWS";
     }
@@ -113,7 +73,7 @@ public:
     // Key functions
     virtual int handleKey(int key)
     {
-        // Set chart mode TWD | TWS
+        // Set chart mode TWD | TWS -> to be implemented
         if (key == 1) {
             if (chrtMode == 'D') {
                 chrtMode = 'S';
@@ -159,9 +119,10 @@ public:
         GwLog* logger = commonData->logger;
 
         float twsValue; // TWS value in chart area
-        String twdName, twdUnit; // TWD name and unit
-        int updFreq; // Update frequency for TWD
-        int16_t twdLowest, twdHighest; // TWD range
+        static String twdName, twdUnit; // TWD name and unit
+        static int updFreq; // Update frequency for TWD
+        static int16_t twdLowest, twdHighest; // TWD range
+        // static int16_t twdBufMinVal; // lowest possible twd buffer value; used for non-set data
 
         static bool isInitialized = false; // Flag to indicate that page is initialized
         static bool wndDataValid = false; // Flag to indicate if wind data is valid
@@ -191,6 +152,7 @@ public:
         static int chrtRng; // Range of wind values from mid wind value to min/max wind value in degrees
         int diffRng; // Difference between mid and current wind value
         static const int dfltRng = 40; // Default range for chart
+        int midWndDir; // New value for wndCenter after chart start / shift
         static int simTwd; // Simulation value for TWD
         static float simTws; // Simulation value for TWS
 
@@ -201,7 +163,7 @@ public:
         static int chrtPrevVal; // Last wind value in chart area for check if value crosses 180 degree line
 
         LOG_DEBUG(GwLog::LOG, "Display page WindPlot");
-        unsigned long start = millis();
+        unsigned long WndPlotStart = millis();
 
         // Get config data
         simulation = config->getBool(config->useSimuData);
@@ -210,11 +172,6 @@ public:
         String backlightMode = config->getString(config->backlight);
 
         if (!isInitialized) {
-
-            if (simulation) {
-                fillSimData(pageData); // Fill the buffer with some test data
-            }
-
             width = getdisplay().width();
             height = getdisplay().height();
             xCenter = width / 2;
@@ -230,8 +187,33 @@ public:
             lastAddedIdx = pageData.boatHstry.twdHstry->getLastIdx();
             pageData.boatHstry.twdHstry->getMetaData(twdName, twdUnit, updFreq, twdLowest, twdHighest);
             wndCenter = INT_MIN;
+            midWndDir = 0;
+            diffRng = dfltRng;
+            chrtRng = dfltRng;
+
             isInitialized = true; // Set flag to indicate that page is now initialized
-            LOG_DEBUG(GwLog::ERROR, "PageWindPlot Start1: lastAddedIdx: %d, simTwd: %.1f, isInitialized: %d, SimData: %d", lastAddedIdx, simTwd / 1000 + radToDeg, isInitialized, simulation);
+        }
+
+        const int numBoatData = 2;
+        GwApi::BoatValue* bvalue;
+        String DataName[numBoatData];
+        double DataValue[numBoatData];
+        bool DataValid[numBoatData];
+        String DataText[numBoatData];
+        String DataUnit[numBoatData];
+        String DataFormat[numBoatData];
+
+        // read boat data values; TWD only for validation test, TWS for display of current value
+        for (int i = 0; i < numBoatData; i++) {
+            bvalue = pageData.values[i];
+            DataName[i] = xdrDelete(bvalue->getName());
+            DataName[i] = DataName[i].substring(0, 6); // String length limit for value name
+            calibrationData.calibrateInstance(bvalue, logger); // Check if boat data value is to be calibrated
+            DataValue[i] = bvalue->value; // Value as double in SI unit
+            DataValid[i] = bvalue->valid;
+            DataText[i] = formatValue(bvalue, *commonData).svalue; // Formatted value as string including unit conversion and switching decimal places
+            DataUnit[i] = formatValue(bvalue, *commonData).unit;
+            DataFormat[i] = bvalue->getFormat(); // Unit of value
         }
 
         // Optical warning by limit violation (unused)
@@ -240,30 +222,11 @@ public:
             setFlashLED(false);
         }
 
-        if (simulation) {
-            simTwd += random(-20, 20);
-            if (simTwd < 0.0)
-                simTwd += 360.0;
-            if (simTwd >= 360.0)
-                simTwd -= 360.0;
-
-            int16_t z = static_cast<int16_t>(DegToRad(simTwd) * 1000.0);
-            LOG_DEBUG(GwLog::ERROR, "PageWindPlot Simulation: getLast TWD: %.0f, lastIdx: %d", pageData.boatHstry.twdHstry->getLast() / 1000.0 * RAD_TO_DEG, pageData.boatHstry.twdHstry->getLastIdx());
-            pageData.boatHstry.twdHstry->add(z); // Fill the buffer with some test data
-            LOG_DEBUG(GwLog::ERROR, "PageWindPlot Simulation: getAdded TWD: %.0f, lastIdx: %d", pageData.boatHstry.twdHstry->getLast() / 1000.0 * RAD_TO_DEG, pageData.boatHstry.twdHstry->getLastIdx());
-
-            simTws += random(-200, 150) / 10.0; // TWS value in knots
-            simTws = constrain(simTws, 0.0f, 50.0f); // Ensure TWS is between 0 and 50 knots
-            twsValue = simTws;
-        } else {
-            twsValue = pageData.boatHstry.twsHstry->getLast() / 10.0 * 1.94384; // TWS value in knots
-        }
-
         // Identify buffer size and buffer start position for chart
         count = pageData.boatHstry.twdHstry->getCurrentSize();
         currIdx = pageData.boatHstry.twdHstry->getLastIdx();
         numAddedBufVals = (currIdx - lastAddedIdx + bufSize) % bufSize; // Number of values added to buffer since last display
-        if (dataIntv != oldDataIntv) {
+        if (dataIntv != oldDataIntv || count == 1) {
             // new data interval selected by user
             intvBufSize = cHeight * dataIntv;
             numWndVals = min(count, (cHeight - 60) * dataIntv);
@@ -277,16 +240,21 @@ public:
                 bufStart = max(0, bufStart - numAddedBufVals);
             }
         }
-        LOG_DEBUG(GwLog::ERROR, "PageWindPlot Dataset: TWD: %.0f, TWS: %.1f, DBT: %.1f, count: %d, intvBufSize: %d, numWndVals: %d, bufStart: %d, numAddedBufVals: %d, lastIdx: %d",
-            pageData.boatHstry.twdHstry->getLast() / 1000.0 * radToDeg, pageData.boatHstry.twsHstry->getLast() / 10.0 * 1.94384, pageData.boatHstry.dbtHstry->getLast() / 10.0,
-            count, intvBufSize, numWndVals, bufStart, numAddedBufVals, pageData.boatHstry.twdHstry->getLastIdx());
+        LOG_DEBUG(GwLog::ERROR, "PageWindPlot Dataset: count: %d, TWD: %.0f, TWS: %.1f, TWD_valid? %d, intvBufSize: %d, numWndVals: %d, bufStart: %d, numAddedBufVals: %d, lastIdx: %d, old: %d, act: %d",
+            count, pageData.boatHstry.twdHstry->getLast() / 1000.0 * radToDeg, pageData.boatHstry.twsHstry->getLast() / 10.0 * 1.94384, DataValid[0],
+            intvBufSize, numWndVals, bufStart, numAddedBufVals, pageData.boatHstry.twdHstry->getLastIdx(), oldDataIntv, dataIntv);
 
-        // initialize chart range values
-        if (wndCenter == INT_MIN) {
-            wndCenter = max(0, int(pageData.boatHstry.twdHstry->get(numWndVals - intvBufSize) / 1000.0 * radToDeg)); // get 1st value of current data interval
-            wndCenter = (int((wndCenter + (wndCenter >= 0 ? 5 : -5)) / 10) * 10) % 360; // Set new center value; round to nearest 10 degree value; 360° -> 0°
-            diffRng = dfltRng;
-            chrtRng = dfltRng;
+        // Set wndCenter from 1st real buffer value
+        if (wndCenter == INT_MIN || (wndCenter == 0 && count == 1)) {
+            midWndDir = pageData.boatHstry.twdHstry->getMid(numWndVals);
+            if (midWndDir != INT16_MIN) {
+                midWndDir = midWndDir / 1000.0 * radToDeg;
+                wndCenter = int((midWndDir + (midWndDir >= 0 ? 5 : -5)) / 10) * 10; // Set new center value; round to nearest 10 degree value
+            } else {
+                wndCenter = 0;
+            }
+            LOG_DEBUG(GwLog::DEBUG, "PageWindPlot Range Init: count: %d, TWD: %.0f, wndCenter: %d, diffRng: %d, chrtRng: %d", count, pageData.boatHstry.twdHstry->getLast() / 1000.0 * radToDeg,
+                wndCenter, diffRng, chrtRng);
         } else {
             // check and adjust range between left, center, and right chart limit
             diffRng = getRng(*pageData.boatHstry.twdHstry, wndCenter, numWndVals);
@@ -304,8 +272,6 @@ public:
         wndRight = (chrtRng < 180 ? wndCenter + chrtRng : wndCenter + chrtRng - 1);
         if (wndRight >= 360)
             wndRight -= 360;
-        LOG_DEBUG(GwLog::DEBUG, "PageWindPlot FirstVal: %f, LastVal: %d, count: %d, diffRng: %d, chartRng: %d, Center: %d, scale: %f", pageData.boatHstry.twdHstry->getFirst() / 1000.0 * radToDeg,
-            pageData.boatHstry.twdHstry->getLast() / 1000.0 * radToDeg, count, diffRng, chrtRng, wndCenter, chrtScl);
 
         // Draw page
         //***********************************************************************
@@ -322,11 +288,9 @@ public:
         char sWndLbl[4]; // char buffer for Wind angle label
         getdisplay().setFont(&Ubuntu_Bold12pt8b);
         getdisplay().setCursor(xCenter - 88, yOffset - 3);
-        getdisplay().print("TWD"); // Wind name
-        // getdisplay().setCursor(xCenter - 20, yOffset - 3);
+        getdisplay().print("TWD"); // Wind data name
         snprintf(sWndLbl, 4, "%03d", (wndCenter < 0) ? (wndCenter + 360) : wndCenter);
         drawTextCenter(xCenter, yOffset - 11, sWndLbl);
-        // getdisplay().print(sWndLbl); // Wind center value
         getdisplay().drawCircle(xCenter + 25, yOffset - 17, 2, commonData->fgcolor); // <degree> symbol
         getdisplay().drawCircle(xCenter + 25, yOffset - 17, 3, commonData->fgcolor); // <degree> symbol
         getdisplay().setCursor(1, yOffset - 3);
@@ -343,7 +307,19 @@ public:
         if (pageData.boatHstry.twdHstry->getMax() == pageData.boatHstry.twdHstry->getMinVal()) {
             // only <INT16_MIN> values in buffer -> no valid wind data available
             wndDataValid = false;
+        } else if (!DataValid[0]) {
+            // currently no valid TWD data available
+            numNoData++;
+            wndDataValid = true;
+            if (numNoData > 3) {
+                // If more than 4 invalid values in a row, send message
+                wndDataValid = false;
+                getdisplay().setFont(&Ubuntu_Bold10pt8b);
+                getdisplay().fillRect(xCenter - 66, height / 2 - 20, 146, 24, commonData->bgcolor); // Clear area for TWS value
+                drawTextCenter(xCenter, height / 2 - 10, "No sensor data");
+            }
         } else {
+            numNoData = 0; // reset data error counter
             wndDataValid = true; // At least some wind data available
         }
         // Draw wind values in chart
@@ -361,17 +337,17 @@ public:
                     }
                     if (numNoData > 4) {
                         // If more than 4 invalid values in a row, send message
-                        getdisplay().setFont(&Ubuntu_Bold10pt7b);
+                        getdisplay().setFont(&Ubuntu_Bold10pt8b);
                         getdisplay().fillRect(xCenter - 66, height / 2 - 20, 146, 24, commonData->bgcolor); // Clear area for TWS value
                         drawTextCenter(xCenter, height / 2 - 10, "No sensor data");
                     } */
                 } else {
-                    chrtVal = (chrtVal / 1000.0 * radToDeg) + 0.5; // Convert to degrees and round
+                    chrtVal = static_cast<int>((chrtVal / 1000.0 * radToDeg) + 0.5); // Convert to degrees and round
                     x = ((chrtVal - wndLeft + 360) % 360) * chrtScl;
                     y = yOffset + cHeight - i; // Position in chart area
 
                     if (i >= (numWndVals / dataIntv) - 10)
-                        LOG_DEBUG(GwLog::ERROR, "PageWindPlot Chart: i: %d, chrtVal: %d, bufStart: %d count: %d, linesToShow: %d", i, chrtVal, bufStart, count, (numWndVals / dataIntv));
+                        LOG_DEBUG(GwLog::DEBUG, "PageWindPlot Chart: i: %d, chrtVal: %d, bufStart: %d, count: %d, linesToShow: %d", i, chrtVal, bufStart, count, (numWndVals / dataIntv));
 
                     if ((i == 0) || (chrtPrevVal == INT16_MIN)) {
                         // just a dot for 1st chart point or after some invalid values
@@ -404,15 +380,15 @@ public:
 
                     int minWndDir = pageData.boatHstry.twdHstry->getMin(numWndVals) / 1000.0 * radToDeg;
                     int maxWndDir = pageData.boatHstry.twdHstry->getMax(numWndVals) / 1000.0 * radToDeg;
-                    LOG_DEBUG(GwLog::ERROR, "PageWindPlot FreeTop: Minimum: %d, Maximum: %d, OldwndCenter: %d", minWndDir, maxWndDir, wndCenter);
-                    if ((minWndDir > wndCenter) || (maxWndDir < wndCenter)) {
+                    LOG_DEBUG(GwLog::DEBUG, "PageWindPlot FreeTop: Minimum: %d, Maximum: %d, OldwndCenter: %d", minWndDir, maxWndDir, wndCenter);
+                    if ((minWndDir + 540 >= wndCenter + 540) || (maxWndDir + 540 <= wndCenter + 540)) {
                         // Check if all wind value are left or right of center value -> optimize chart range
-                        int midWndDir = pageData.boatHstry.twdHstry->getMid(numWndVals) / 1000.0 * radToDeg;
+                        midWndDir = pageData.boatHstry.twdHstry->getMid(numWndVals) / 1000.0 * radToDeg;
                         if (midWndDir != INT16_MIN) {
                             wndCenter = int((midWndDir + (midWndDir >= 0 ? 5 : -5)) / 10) * 10; // Set new center value; round to nearest 10 degree value
                         }
                     }
-                    LOG_DEBUG(GwLog::ERROR, "PageWindPlot FreeTop: cHeight: %d, bufStart: %d, numWndVals: %d, wndCenter: %d", cHeight, bufStart, numWndVals, wndCenter);
+                    LOG_DEBUG(GwLog::DEBUG, "PageWindPlot FreeTop: cHeight: %d, bufStart: %d, numWndVals: %d, wndCenter: %d", cHeight, bufStart, numWndVals, wndCenter);
                     break;
                 }
             }
@@ -433,6 +409,8 @@ public:
             int xPosTws;
             static const int yPosTws = yOffset + 40;
 
+            twsValue = pageData.boatHstry.twsHstry->getLast() / 10.0 * 1.94384; // TWS value in knots
+
             xPosTws = flipTws ? 20 : width - 138;
             currentZone = (y >= yPosTws - 38) && (y <= yPosTws + 6) && (x >= xPosTws - 4) && (x <= xPosTws + 146) ? 1 : 0; // Define current zone for TWS value
             if (currentZone != lastZone) {
@@ -447,21 +425,24 @@ public:
             getdisplay().fillRect(xPosTws - 4, yPosTws - 38, 142, 44, commonData->bgcolor); // Clear area for TWS value
             getdisplay().setFont(&DSEG7Classic_BoldItalic16pt7b);
             getdisplay().setCursor(xPosTws, yPosTws);
-            if (twsValue < 0 || twsValue >= 100) {
+            if (!DataValid[1]) {
                 getdisplay().print("--.-");
             } else {
-                if (twsValue < 10.0) {
-                    getdisplay().printf("!%3.1f", twsValue); // Value
+                if (DataValue[1] < 9.95) {
+                    getdisplay().printf("!%3.1f", DataValue[1] + 0.05); // Value, round to 1 decimal
                 } else {
-                    getdisplay().printf("%4.1f", twsValue); // Value}
+                    getdisplay().printf("%4.1f", DataValue[1] + 0.05); // Value, round to 1 decimal
                 }
             }
             getdisplay().setFont(&Ubuntu_Bold12pt8b);
             getdisplay().setCursor(xPosTws + 82, yPosTws - 14);
-            getdisplay().print("TWS"); // Name
+//            getdisplay().print("TWS"); // Name
+            getdisplay().print(DataName[1]); // Name
             getdisplay().setFont(&Ubuntu_Bold8pt8b);
-            getdisplay().setCursor(xPosTws + 78, yPosTws + 1);
-            getdisplay().printf(" kn"); // Unit
+//            getdisplay().setCursor(xPosTws + 78, yPosTws + 1);
+            getdisplay().setCursor(xPosTws + 82, yPosTws + 1);
+//            getdisplay().printf(" kn"); // Unit
+            getdisplay().print(DataUnit[1]); // Unit
         }
 
         // chart Y axis labels; print at last to overwrite potential chart lines in label area
@@ -471,7 +452,7 @@ public:
         for (int i = 1; i <= 3; i++) {
             yPos = yOffset + (i * 60);
             getdisplay().fillRect(0, yPos, width, 1, commonData->fgcolor);
-            getdisplay().fillRect(0, yPos - 8, 26, 16, commonData->bgcolor); // Clear small area to remove potential chart lines
+            getdisplay().fillRect(0, yPos - 8, 24, 16, commonData->bgcolor); // Clear small area to remove potential chart lines
             getdisplay().setCursor(1, yPos + 4);
             if (count >= intvBufSize) {
                 // Calculate minute value for label
@@ -483,8 +464,8 @@ public:
             getdisplay().printf("%3d", chrtLbl); // Wind value label
         }
 
-        unsigned long finish = millis() - start;
-//        LOG_DEBUG(GwLog::ERROR, "PageWindPlot Time: %lu", finish);
+        unsigned long finish = millis() - WndPlotStart;
+        LOG_DEBUG(GwLog::ERROR, "PageWindPlot Time: %lu", finish);
         // Update display
         getdisplay().nextPage(); // Partial update (fast)
     };
@@ -505,9 +486,9 @@ PageDescription registerPageWindPlot(
     "WindPlot", // Page name
     createPage, // Action
     0, // Number of bus values depends on selection in Web configuration
-//    { "TWD", "TWA", "TWS", "HDM", "AWA", "AWS", "STW", "COG", "SOG" }, // Bus values we need in the page
-    { }, // Bus values we need in the page
+    { "TWD", "TWS" }, // Bus values we need in the page
+//    {}, // Bus values we need in the page
     true // Show display header on/off
 );
 
-#endif
+#endif
\ No newline at end of file
diff --git a/lib/obp60task/Pagedata.h b/lib/obp60task/Pagedata.h
index e518221..ad252ea 100644
--- a/lib/obp60task/Pagedata.h
+++ b/lib/obp60task/Pagedata.h
@@ -5,15 +5,10 @@
 #include <vector>
 #include "LedSpiTask.h"
 #include "OBPRingBuffer.h"
+#include "OBPDataOperations.h"
 
 #define MAX_PAGE_NUMBER 10    // Max number of pages for show data
 
-typedef struct{
-  RingBuffer<int16_t>* twdHstry;
-  RingBuffer<int16_t>* twsHstry;
-  RingBuffer<int16_t>* dbtHstry;
-} tBoatHstryData;
-
 typedef std::vector<GwApi::BoatValue *> ValueList;
 
 typedef struct{
diff --git a/lib/obp60task/config.json b/lib/obp60task/config.json
index da8be86..c1f9ab8 100644
--- a/lib/obp60task/config.json
+++ b/lib/obp60task/config.json
@@ -219,6 +219,17 @@
             "obp60":"true"
         }
     },
+    {
+        "name": "calcTrueWnds",
+        "label": "Calculate True Wind",
+        "type": "boolean",
+        "default": "false",
+        "description": "If not available, calculate true wind data from appearant wind and other boat data",
+        "category": "OBP60 Settings",
+        "capabilities": {
+            "obp60": "true"
+        }
+    },
     {
         "name": "lengthFormat",
         "label": "Length Format",
diff --git a/lib/obp60task/config_obp40.json b/lib/obp60task/config_obp40.json
index 782e7f0..8747e4e 100644
--- a/lib/obp60task/config_obp40.json
+++ b/lib/obp60task/config_obp40.json
@@ -219,6 +219,17 @@
             "obp40": "true"
         }
     },
+    {
+        "name": "calcTrueWnds",
+        "label": "Calculate True Wind",
+        "type": "boolean",
+        "default": "false",
+        "description": "If not available, calculate true wind data from appearant wind and other boat data",
+        "category": "OBP40 Settings",
+        "capabilities": {
+            "obp40": "true"
+        }
+    },
     {
         "name": "lengthFormat",
         "label": "Length Format",
diff --git a/lib/obp60task/obp60task.cpp b/lib/obp60task/obp60task.cpp
index 2d4e72b..505d89c 100644
--- a/lib/obp60task/obp60task.cpp
+++ b/lib/obp60task/obp60task.cpp
@@ -376,6 +376,112 @@ void underVoltageDetection(GwApi *api, CommonData &common){
     }
 }
 
+//bool addTrueWind(GwApi* api, BoatValueList* boatValues, double *twd, double *tws, double *twa) {
+bool addTrueWind(GwApi* api, BoatValueList* boatValues) {
+    // Calculate true wind data and add to obp60task boat data list
+
+    double awaVal, awsVal, cogVal, stwVal, sogVal, hdtVal, hdmVal, varVal;
+    bool isCalculated = false;
+    const double DBL_MIN = std::numeric_limits<double>::lowest();
+
+    GwApi::BoatValue *twdBVal = boatValues->findValueOrCreate("TWD");
+    GwApi::BoatValue *twsBVal = boatValues->findValueOrCreate("TWS");
+    GwApi::BoatValue *twaBVal = boatValues->findValueOrCreate("TWA");
+    GwApi::BoatValue *awaBVal = boatValues->findValueOrCreate("AWA");
+    GwApi::BoatValue *awsBVal = boatValues->findValueOrCreate("AWS");
+    GwApi::BoatValue *cogBVal = boatValues->findValueOrCreate("COG");
+    GwApi::BoatValue *stwBVal = boatValues->findValueOrCreate("STW");
+    GwApi::BoatValue *sogBVal = boatValues->findValueOrCreate("SOG");
+    GwApi::BoatValue *hdtBVal = boatValues->findValueOrCreate("HDT");
+    GwApi::BoatValue *hdmBVal = boatValues->findValueOrCreate("HDM");
+    GwApi::BoatValue *varBVal = boatValues->findValueOrCreate("VAR");
+    awaVal = awaBVal->valid ? awaBVal->value : DBL_MIN;
+    awsVal = awsBVal->valid ? awsBVal->value : DBL_MIN;
+    cogVal = cogBVal->valid ? cogBVal->value : DBL_MIN;
+    stwVal = stwBVal->valid ? stwBVal->value : DBL_MIN;
+    sogVal = sogBVal->valid ? sogBVal->value : DBL_MIN;
+    hdtVal = hdtBVal->valid ? hdtBVal->value : DBL_MIN;
+    hdmVal = hdmBVal->valid ? hdmBVal->value : DBL_MIN;
+    varVal = varBVal->valid ? varBVal->value : DBL_MIN;
+    api->getLogger()->logDebug(GwLog::ERROR,"obp60task addTrueWind: AWA: %.1f, AWS: %.1f, COG: %.1f, STW: %.1f, HDT: %.1f, HDM: %.1f, VAR: %.1f", awaBVal->value * RAD_TO_DEG, awsBVal->value * 3.6 / 1.852,
+            cogBVal->value * RAD_TO_DEG, stwBVal->value * 3.6 / 1.852, hdtBVal->value * RAD_TO_DEG, hdmBVal->value * RAD_TO_DEG, varBVal->value * RAD_TO_DEG);
+
+    isCalculated = WindUtils::calcTrueWind(&awaVal, &awsVal, &cogVal, &stwVal, &sogVal, &hdtVal, &hdmVal, &varVal, &twdBVal->value, &twsBVal->value, &twaBVal->value);
+    twdBVal->valid = isCalculated;
+    twsBVal->valid = isCalculated;
+    twaBVal->valid = isCalculated;
+
+    api->getLogger()->logDebug(GwLog::ERROR,"obp60task calcTrueWind: TWD_Valid? %d, TWD=%.1f, TWS=%.1f, TWA=%.1f, isCalculated? %d", twdBVal->valid, twdBVal->value * RAD_TO_DEG, twsBVal->value * 3.6 / 1.852,
+        twaBVal->value * RAD_TO_DEG, isCalculated);
+
+    return isCalculated;
+}
+
+void initHstryBuf(GwApi* api, BoatValueList* boatValues, tBoatHstryData hstryBufList) {
+    // Init history buffers for TWD, TWS
+
+    GwApi::BoatValue *calBVal; // temp variable just for data calibration -> we don't want to calibrate the original data here
+
+    int hstryUpdFreq = 1000; // Update frequency for history buffers in ms
+    int hstryMinVal = 0; // Minimum value for these history buffers
+    int twdHstryMax = 6283; // Max value for wind direction (TWD) in rad (0...2*PI), shifted by 1000 for 3 decimals
+    int twsHstryMax = 1000; // Max value for wind speed (TWS) in m/s, shifted by 10 for 1 decimal
+    // Initialize history buffers with meta data
+    hstryBufList.twdHstry->setMetaData("TWD", "formatCourse", hstryUpdFreq, hstryMinVal, twdHstryMax);
+    hstryBufList.twsHstry->setMetaData("TWS", "formatKnots", hstryUpdFreq, hstryMinVal, twsHstryMax);
+
+    GwApi::BoatValue *twdBVal = boatValues->findValueOrCreate(hstryBufList.twdHstry->getName());
+    GwApi::BoatValue *twsBVal = boatValues->findValueOrCreate(hstryBufList.twsHstry->getName());
+    GwApi::BoatValue *twaBVal = boatValues->findValueOrCreate("TWA");
+}
+
+void handleHstryBuf(GwApi* api, BoatValueList* boatValues, tBoatHstryData hstryBufList) {
+    // Handle history buffers for TWD, TWS
+
+    GwLog *logger = api->getLogger();
+
+    int16_t twdHstryMin = hstryBufList.twdHstry->getMinVal();
+    int16_t twdHstryMax = hstryBufList.twdHstry->getMaxVal();
+    int16_t twsHstryMin = hstryBufList.twsHstry->getMinVal();
+    int16_t twsHstryMax = hstryBufList.twsHstry->getMaxVal();
+    int16_t twdBuf, twsBuf;
+    GwApi::BoatValue *calBVal; // temp variable just for data calibration -> we don't want to calibrate the original data here
+
+    GwApi::BoatValue *twdBVal = boatValues->findValueOrCreate(hstryBufList.twdHstry->getName());
+    GwApi::BoatValue *twsBVal = boatValues->findValueOrCreate(hstryBufList.twsHstry->getName());
+    GwApi::BoatValue *twaBVal = boatValues->findValueOrCreate("TWA");
+
+    api->getLogger()->logDebug(GwLog::ERROR,"obp60task handleHstryBuf: twdBVal: %f, twsBVal: %f, twaBVal: %f, TWD_isValid? %d", twdBVal->value * RAD_TO_DEG,
+        twsBVal->value * 3.6 / 1.852, twaBVal->value * RAD_TO_DEG, twdBVal->valid);
+    calBVal = new GwApi::BoatValue("TWD"); // temporary solution for calibration of history buffer values
+    calBVal->setFormat(twdBVal->getFormat());
+    if (twdBVal->valid) {
+        calBVal->value = twdBVal->value;
+        calBVal->valid = twdBVal->valid;
+        calibrationData.calibrateInstance(calBVal, logger); // Check if boat data value is to be calibrated
+        twdBuf = static_cast<int16_t>(std::round(calBVal->value * 1000));
+        if (twdBuf >= twdHstryMin && twdBuf <= twdHstryMax) {
+            hstryBufList.twdHstry->add(twdBuf);
+        }
+    }
+    delete calBVal;
+    calBVal = nullptr;
+
+    calBVal = new GwApi::BoatValue("TWS"); // temporary solution for calibration of history buffer values
+    calBVal->setFormat(twsBVal->getFormat());
+    if (twsBVal->valid) {
+        calBVal->value = twsBVal->value;
+        calBVal->valid = twsBVal->valid;
+        calibrationData.calibrateInstance(calBVal, logger); // Check if boat data value is to be calibrated
+        twsBuf = static_cast<int16_t>(std::round(calBVal->value * 10));
+        if (twsBuf >= twsHstryMin && twsBuf <= twsHstryMax) {
+            hstryBufList.twsHstry->add(twsBuf);
+        }
+    }
+    delete calBVal;
+    calBVal = nullptr;
+}
+
 // OBP60 Task
 //####################################################################################
 void OBP60Task(GwApi *api){
@@ -392,11 +498,6 @@ void OBP60Task(GwApi *api){
     commonData.logger=logger;
     commonData.config=config;
 
-    // Create ring buffers for history storage of some boat data
-    RingBuffer<int16_t> twdHstry(960); // Circular buffer to store wind direction values; store 960 TWD values for 16 minutes history
-    RingBuffer<int16_t> twsHstry(960); // Circular buffer to store wind speed values (TWS)
-    RingBuffer<int16_t> dbtHstry(960); // Circular buffer to store water depth values (DBT)
-
 #ifdef HARDWARE_V21
     // Keyboard coordinates for page footer
     initKeys(commonData);
@@ -494,6 +595,11 @@ void OBP60Task(GwApi *api){
     //commonData.distanceformat=config->getString(xxx);
     //add all necessary data to common data
 
+    // Create ring buffers for history storage of some boat data
+    RingBuffer<int16_t> twdHstry(960); // Circular buffer to store wind direction values; store 960 TWD values for 16 minutes history
+    RingBuffer<int16_t> twsHstry(960); // Circular buffer to store wind speed values (TWS)
+    tBoatHstryData hstryBufList = {&twdHstry, &twsHstry};
+
     //fill the page data from config
     numPages=config->getInt(config->visiblePages,1);
     if (numPages < 1) numPages=1;
@@ -532,8 +638,10 @@ void OBP60Task(GwApi *api){
             LOG_DEBUG(GwLog::DEBUG,"added fixed value %s to page %d",value->getName().c_str(),i);
             pages[i].parameters.values.push_back(value); 
        }
-        // Add boat history data to page parameters
-        pages[i].parameters.boatHstry = {&twdHstry, &twsHstry, &dbtHstry};
+        if (pages[i].description->pageName == "WindPlot") {
+            // Add boat history data to page parameters
+            pages[i].parameters.boatHstry = hstryBufList;
+        }
     }
     // add out of band system page (always available)
     Page *syspage = allPages.pages[0]->creator(commonData);
@@ -541,32 +649,12 @@ void OBP60Task(GwApi *api){
     // Read all calibration data settings from config
     calibrationData.readConfig(config, logger);
 
-    // List of boat values for history storage
-    GwApi::BoatValue *twdBVal=new GwApi::BoatValue(GwBoatData::_TWD);
-    GwApi::BoatValue *twsBVal=new GwApi::BoatValue(GwBoatData::_TWS);
-    GwApi::BoatValue *dbtBVal=new GwApi::BoatValue(GwBoatData::_DBT);
-    GwApi::BoatValue *hstryValList[]={twdBVal, twsBVal, dbtBVal};
-    api->getBoatDataValues(3, hstryValList);
-    // Boat data history buffer initialization
-    int hstryUpdFreq = 1000; // Update frequency for history buffers in ms
-    int hstryMinVal = 0; // Minimum value for these history buffers
-    int twdHstryMax = 6283; // Max value for wind direction (TWD) in rad (0...2*PI), shifted by 1000 for 3 decimals
-    int twsHstryMax = 1000; // Max value for wind speed (TWS) in m/s, shifted by 10 for 1 decimal
-    int dbtHstryMax = 3276; // Max value for depth in m (=327), shifted by 10 for 1 decimal
-    // Initialize history buffers with meta data
-    twdHstry.setMetaData(twdBVal->getName(), twdBVal->getFormat(), hstryUpdFreq, hstryMinVal, twdHstryMax);
-    twsHstry.setMetaData(twsBVal->getName(), twsBVal->getFormat(), hstryUpdFreq, hstryMinVal, twsHstryMax);
-    dbtHstry.setMetaData(dbtBVal->getName(), dbtBVal->getFormat(), hstryUpdFreq, hstryMinVal, dbtHstryMax);
-    bool simulation = api->getConfig()->getBool(api->getConfig()->useSimuData, false);
+    // Check user setting for true wind calculation
+    bool calcTrueWnds = api->getConfig()->getBool(api->getConfig()->calcTrueWnds, false);
+    // bool simulation = api->getConfig()->getBool(api->getConfig()->useSimuData, false);
 
-    // List of boat values for true winds calculation
-    GwApi::BoatValue *awaBVal=new GwApi::BoatValue(GwBoatData::_AWA);
-    GwApi::BoatValue *awsBVal=new GwApi::BoatValue(GwBoatData::_AWS);
-    GwApi::BoatValue *cogBVal=new GwApi::BoatValue(GwBoatData::_COG);
-    GwApi::BoatValue *stwBVal=new GwApi::BoatValue(GwBoatData::_STW);
-    GwApi::BoatValue *hdtBVal=new GwApi::BoatValue(GwBoatData::_HDT);
-    GwApi::BoatValue *hdmBVal=new GwApi::BoatValue(GwBoatData::_HDM);
-    GwApi::BoatValue *WndCalcValList[]={awaBVal, awsBVal, cogBVal, stwBVal, hdtBVal, hdmBVal};
+    // Initialize history buffer for certain boat data
+    initHstryBuf(api, &boatValues, hstryBufList);
 
     // Display screenshot handler for HTTP request
     // http://192.168.15.1/api/user/OBP60Task/screenshot
@@ -623,18 +711,6 @@ void OBP60Task(GwApi *api){
     GwApi::BoatValue *lon = boatValues.findValueOrCreate("LON");        // Load GpsLongitude
     GwApi::BoatValue *hdop = boatValues.findValueOrCreate("HDOP");       // Load GpsHDOP
 
-/*    // Boat values for wind conversion for main loop; will be calculated in case values are not available by sensors
-    GwApi::BoatValue *twd = boatValues.findValueOrCreate("TWD");        // True Wind Direction
-    GwApi::BoatValue *tws = boatValues.findValueOrCreate("TWS");        // True Wind Speed
-    GwApi::BoatValue *twa = boatValues.findValueOrCreate("TWA");        // True Wind Angle
-    GwApi::BoatValue *awaBVal = boatValues.findValueOrCreate("AWA");        // Apparent Wind Angle
-    GwApi::BoatValue *awsBVal = boatValues.findValueOrCreate("AWS");        // Apparent Wind Speed
-    GwApi::BoatValue *cogBVal = boatValues.findValueOrCreate("COG");        // Course Over Ground
-    GwApi::BoatValue *stwBVal = boatValues.findValueOrCreate("STW");        // Speed Through Water
-    GwApi::BoatValue *hdtBVal = boatValues.findValueOrCreate("HDT");        // Heading True
-    GwApi::BoatValue *ctwBVal = boatValues.findValueOrCreate("CTW");        // Course Through Water
-    GwApi::BoatValue *hdmBVal = boatValues.findValueOrCreate("HDM");        // Heading Magnetic
-*/
     LOG_DEBUG(GwLog::LOG,"obp60task: start mainloop");
     
     commonData.time = boatValues.findValueOrCreate("GPST");      // Load GpsTime
@@ -648,7 +724,6 @@ void OBP60Task(GwApi *api){
     long starttime3 = millis();     // Display update all 1s
     long starttime4 = millis();     // Delayed display update after 4s when select a new page
     long starttime5 = millis();     // Calculate sunrise and sunset all 1s
-    unsigned long starttime10 = millis(); // Get history TWD, TWS, DBT data and calculate true winds each 1s
 
     pages[pageNumber].page->setupKeys(); // Initialize keys for first page
 
@@ -836,62 +911,8 @@ void OBP60Task(GwApi *api){
                     getdisplay().fillScreen(commonData.bgcolor); // Clear display
                     getdisplay().nextPage();                     // Full update
                 }
-            }
-            
-            // Read TWD, TWS, DBT data from boatData each 1000ms for history and windplot display
-            if((millis() > starttime10 + 1000) && !simulation) {
-                double twdVal, twsVal, dbtVal;
-                double awaVal, awsVal, cogVal, stwVal, hdtVal, hdmVal;
-                double DBL_MIN = std::numeric_limits<double>::lowest();
-
-                starttime10 = millis();
-                LOG_DEBUG(GwLog::DEBUG,"History buffer write cycle");
-                api->getBoatDataValues(3, hstryValList);
-
-                if (!twdBVal->valid || !twsBVal->valid) {
-                    api->getBoatDataValues(6, WndCalcValList); // Get all values for true wind calculation
-                    awaVal = awaBVal->valid ? awaBVal->value * RAD_TO_DEG : __DBL_MIN__;
-                    awsVal = awsBVal->valid ? awsBVal->value : __DBL_MIN__;
-                    cogVal = cogBVal->valid ? cogBVal->value  * RAD_TO_DEG : __DBL_MIN__;
-                    stwVal = stwBVal->valid ? stwBVal->value : __DBL_MIN__;
-                    hdtVal = hdtBVal->valid ? hdtBVal->value * RAD_TO_DEG : __DBL_MIN__;
-                    hdmVal = hdmBVal->valid ? hdmBVal->value * RAD_TO_DEG : __DBL_MIN__; 
-                    LOG_DEBUG(GwLog::ERROR,"obp60task - Read data: AWA: %f, AWS: %f, COG: %f, STW: %f, HDT: %f, TWD=%f, TWS=%f", awaBVal->value, awsBVal->value,
-                            cogBVal->value, stwBVal->value, hdtBVal->value, twdBVal->value, twsBVal->value);
-
-                    bool isCalculated = WindUtils::calcTrueWind(&awaVal, &awsVal, &cogVal, &stwVal, &cogVal, &hdmVal, &twdVal, &twsVal); // Calculate true wind if TWD not available
-//                    bool isCalculated = WindUtils::calcTrueWind(&awaVal, &awsVal, &cogVal, &stwVal, &hdtVal, &hdmVal, &twdVal, &twsVal); // Calculate true wind if TWD not available
-                    LOG_DEBUG(GwLog::ERROR,"obp60task - calc Wind: AWA: %f, AWS: %f, COG: %f, STW: %f, HDT: %f, TWD=%f, TWS=%f, converted? %d", awaBVal->value * RAD_TO_DEG, awsBVal->value * 3.6 / 1.852,
-                            cogBVal->value * RAD_TO_DEG, stwBVal->value * 3.6 / 1.852, hdtBVal->value * RAD_TO_DEG, twdVal, twsVal, isCalculated);
-                }
-                if (twdBVal->valid) {
-                    twdVal = std::round(twdBVal->value * 1000); // Shift value to store decimals in int16_t);
-                    if (twdVal < hstryMinVal || twdVal > twdHstryMax) {
-                        twdVal = INT16_MIN; // Add invalid value
-                    }
-                }
-                twdHstry.add(static_cast<int16_t>(twdVal));
-
-                if (twsBVal->valid) {
-                    twsVal = static_cast<int16_t>(twsBVal->value * 10); // Shift value to store decimals in int16_t
-                    if (twsVal < hstryMinVal || twsVal > twsHstryMax) {
-                        twsVal = INT16_MIN; // Add invalid value
-                    }
-                }
-                twsHstry.add(twsVal);
-
-                if (dbtBVal->valid) {
-                    dbtVal = dbtBVal->value * 10; // Shift value to store decimals in int16_t
-                    if (dbtVal < hstryMinVal || dbtVal > dbtHstryMax) {
-                        dbtVal = INT16_MIN; // Add invalid value
-                    }
-                    dbtHstry.add(dbtVal);
-                }
-
-                int counttime = millis() - starttime10;
-                LOG_DEBUG(GwLog::ERROR,"obp60task: History buffer write time: %d", counttime);
-            }
-
+            }        
+                
             // Refresh display data, default all 1s
             currentPage = pages[pageNumber].page;
             int pagetime = 1000;
@@ -907,6 +928,12 @@ void OBP60Task(GwApi *api){
                 api->getBoatDataValues(boatValues.numValues,boatValues.allBoatValues);
                 api->getStatus(commonData.status);
 
+                if (calcTrueWnds) {
+                    addTrueWind(api, &boatValues);
+                }
+                // Handle history buffers for TWD, TWS for wind plot page and other usage
+                 handleHstryBuf(api, &boatValues, hstryBufList);
+
                 // Clear display
                 // getdisplay().fillRect(0, 0, getdisplay().width(), getdisplay().height(), commonData.bgcolor);
                 getdisplay().fillScreen(commonData.bgcolor);  // Clear display