diff --git a/gui_qt/formwater.cpp b/gui_qt/formwater.cpp
index 97c5801..4935a4d 100644
--- a/gui_qt/formwater.cpp
+++ b/gui_qt/formwater.cpp
@@ -2,11 +2,16 @@
 #include "formwater.h"
 #include "ui_formwater.h"
 #include <QColor>
+#include <math.h>
 
 #include "../lib_paysages/water.h"
 #include "../lib_paysages/shared/functions.h"
+#include "../lib_paysages/shared/constants.h"
 
-class PreviewCoverage:private Preview
+static WaterDefinition _definition;
+
+/**************** Previews ****************/
+class PreviewCoverage:public Preview
 {
 public:
     PreviewCoverage(QWidget* parent):
@@ -19,32 +24,159 @@ protected:
         double height;
 
         height = terrainGetHeight(x, y);
-        if (height > 0.0)
+        if (height > _definition.height)
         {
             height = terrainGetHeightNormalized(x, y);
             return QColor((int)(255.0 * height), (int)(255.0 * height), (int)(255.0 * height));
         }
         else
         {
-            return QColor(0, 0, 255);
+            return QColor(_definition.main_color.r * 255.0, _definition.main_color.g * 255.0, _definition.main_color.b * 255.0);
         }
     }
 };
 
+class PreviewColor:public Preview
+{
+public:
+    PreviewColor(QWidget* parent):
+        Preview(parent)
+    {
+    }
+protected:
+    QColor getColor(double x, double y)
+    {
+        Vector3 eye, look, location;
+        WaterDefinition definition;
+        WaterEnvironment environment;
+        WaterQuality quality;
+        Color result;
+
+        eye.x = 0.0;
+        eye.y = scaling;
+        eye.z = -10.0 * scaling;
+        look.x = x * 0.01 / scaling;
+        look.y = -y * 0.01 / scaling - 0.3;
+        look.z = 1.0;
+        look = v3Normalize(look);
+
+        if (look.y > -0.0001)
+        {
+            result = this->rayCastFromWater(eye, look).hit_color;
+            return QColor(result.r * 255.0, result.g * 255.0, result.b * 255.0);
+        }
+
+        location.x = eye.x - look.x * eye.y / look.y;
+        location.y = 0.0;
+        location.z = eye.z - look.z * eye.y / look.y;
+
+        if (location.z > 0.0)
+        {
+            result = this->rayCastFromWater(eye, look).hit_color;
+            return QColor(result.r * 255.0, result.g * 255.0, result.b * 255.0);
+        }
+
+        definition = _definition;
+        definition.height = 0.0;
+        environment.reflection_function = (RayCastingFunction)(&this->rayCastFromWater);
+        environment.refraction_function = (RayCastingFunction)(&this->rayCastFromWater);
+        environment.toggle_fog = 0;
+        environment.toggle_shadows = 0;
+        quality.force_detail = 0.0001;
+
+        result = waterGetColorCustom(location, look, &definition, &quality, &environment).final;
+        return QColor(result.r * 255.0, result.g * 255.0, result.b * 255.0);
+    }
+
+private:
+    static RayCastingResult rayCastFromWater(Vector3 start, Vector3 direction)
+    {
+        RayCastingResult result;
+        double x, y;
+
+        result.hit = 1;
+        if (direction.z < 0.0001)
+        {
+            result.hit_color = COLOR_WHITE;
+        }
+        else
+        {
+            x = start.x + direction.x * (0.0 - start.z) / direction.z;
+            y = start.y + direction.y * (0.0 - start.z) / direction.z;
+
+            if (((int)ceil(x * 0.2) % 2 == 0) ^ ((int)ceil(y * 0.2 - 0.5) % 2 == 0))
+            {
+                result.hit_color = COLOR_WHITE;
+            }
+            else
+            {
+                result.hit_color = COLOR_GREY;
+            }
+        }
+        /* TODO hit_location */
+
+        return result;
+    }
+};
+
+/**************** Form ****************/
 FormWater::FormWater(QWidget *parent) :
     QWidget(parent),
     ui(new Ui::FormWater)
 {
-    PreviewCoverage* previewCoverage;
-
     ui->setupUi(this);
 
-    this->findChild<QToolBox*>("water_configs")->setCurrentIndex(0);
+    findChild<QToolBox*>("water_configs")->setCurrentIndex(0);
 
-    previewCoverage = new PreviewCoverage(this->findChild<QWidget*>("water_preview_coverage"));
+    _definition = waterCreateDefinition();
+
+    previewCoverage = new PreviewCoverage(findChild<QWidget*>("water_preview_coverage"));
+    previewColor = new PreviewColor(findChild<QWidget*>("water_preview_color"));
+
+    QObject::connect(findChild<QSlider*>("water_height"), SIGNAL(valueChanged(int)), this, SLOT(configChange()));
+    QObject::connect(findChild<QSlider*>("water_transparency"), SIGNAL(valueChanged(int)), this, SLOT(configChange()));
+    QObject::connect(findChild<QSlider*>("water_reflection"), SIGNAL(valueChanged(int)), this, SLOT(configChange()));
+    QObject::connect(findChild<QSlider*>("water_depth_limit"), SIGNAL(valueChanged(int)), this, SLOT(configChange()));
+
+    revertConfig();
 }
 
 FormWater::~FormWater()
 {
     delete ui;
 }
+
+void FormWater::dataUpdated()
+{
+    revertConfig();
+}
+
+void FormWater::configChange()
+{
+    _definition.height = (double)findChild<QSlider*>("water_height")->value() / 10.0;
+    _definition.transparency = (double)findChild<QSlider*>("water_transparency")->value() / 1000.0;
+    _definition.reflection = (double)findChild<QSlider*>("water_reflection")->value() / 1000.0;
+    _definition.transparency_depth = (double)findChild<QSlider*>("water_depth_limit")->value() / 10.0;
+
+    previewCoverage->redraw();
+    previewColor->redraw();
+}
+
+void FormWater::applyConfig()
+{
+    waterSetDefinition(_definition);
+    //guiUpdate();
+}
+
+void FormWater::revertConfig()
+{
+    waterCopyDefinition(waterGetDefinition(), &_definition);
+
+    findChild<QSlider*>("water_height")->setValue(_definition.height * 10.0);
+    findChild<QSlider*>("water_transparency")->setValue(_definition.transparency * 1000.0);
+    findChild<QSlider*>("water_reflection")->setValue(_definition.reflection * 1000.0);
+    findChild<QSlider*>("water_depth_limit")->setValue(_definition.transparency_depth * 10.0);
+
+    previewCoverage->redraw();
+    previewColor->redraw();
+}
diff --git a/gui_qt/formwater.h b/gui_qt/formwater.h
index ef499c6..1948b33 100644
--- a/gui_qt/formwater.h
+++ b/gui_qt/formwater.h
@@ -2,6 +2,7 @@
 #define FORMWATER_H
 
 #include <QWidget>
+#include "preview.h"
 
 namespace Ui {
     class FormWater;
@@ -15,8 +16,17 @@ public:
     explicit FormWater(QWidget *parent = 0);
     ~FormWater();
 
+    void dataUpdated();
+
+public slots:
+    void configChange();
+    void applyConfig();
+    void revertConfig();
+
 private:
     Ui::FormWater *ui;
+    Preview* previewCoverage;
+    Preview* previewColor;
 };
 
 #endif // FORMWATER_H
diff --git a/gui_qt/formwater.ui b/gui_qt/formwater.ui
index d3ade26..6557ab9 100644
--- a/gui_qt/formwater.ui
+++ b/gui_qt/formwater.ui
@@ -156,8 +156,8 @@
      <rect>
       <x>0</x>
       <y>0</y>
-      <width>98</width>
-      <height>28</height>
+      <width>451</width>
+      <height>438</height>
      </rect>
     </property>
     <attribute name="label">
@@ -185,6 +185,12 @@
       </item>
       <item row="0" column="1">
        <widget class="QSlider" name="water_height">
+        <property name="minimum">
+         <number>-300</number>
+        </property>
+        <property name="maximum">
+         <number>300</number>
+        </property>
         <property name="orientation">
          <enum>Qt::Horizontal</enum>
         </property>
@@ -198,8 +204,8 @@
      <rect>
       <x>0</x>
       <y>0</y>
-      <width>98</width>
-      <height>28</height>
+      <width>451</width>
+      <height>438</height>
      </rect>
     </property>
     <attribute name="label">
@@ -315,7 +321,7 @@
       <item row="4" column="1">
        <widget class="QSlider" name="water_depth_limit">
         <property name="maximum">
-         <number>50</number>
+         <number>500</number>
         </property>
         <property name="orientation">
          <enum>Qt::Horizontal</enum>
@@ -324,7 +330,7 @@
          <enum>QSlider::TicksBelow</enum>
         </property>
         <property name="tickInterval">
-         <number>1</number>
+         <number>10</number>
         </property>
        </widget>
       </item>
diff --git a/gui_qt/main.cc b/gui_qt/main.cc
index 1f9bbf6..279d6fa 100644
--- a/gui_qt/main.cc
+++ b/gui_qt/main.cc
@@ -6,11 +6,11 @@
 
 int main(int argc, char** argv)
 {
+    paysagesInit();
+
     QApplication app(argc, argv);
     MainWindow window;
 
-    paysagesInit();
-
     window.show();
 
     Preview::startUpdater();
diff --git a/gui_qt/preview.cpp b/gui_qt/preview.cpp
index ef0c802..140747e 100644
--- a/gui_qt/preview.cpp
+++ b/gui_qt/preview.cpp
@@ -15,9 +15,9 @@ public:
 protected:
     void run()
     {
-        QVectorIterator<Preview*> iter(_previews);
         while (true)
         {
+            QVectorIterator<Preview*> iter(_previews);
             while (iter.hasNext())
             {
                 iter.next()->doRender();
@@ -68,6 +68,13 @@ void Preview::doRender()
     }
 }
 
+void Preview::redraw()
+{
+    lock->lock();
+    need_rerender = 1;
+    lock->unlock();
+}
+
 void Preview::resizeEvent(QResizeEvent* event)
 {
     QImage* image;
@@ -307,13 +314,6 @@ void Preview::renderPixbuf()
 //    return 1;
 //}
 
-//void guiPreviewRedraw(SmallPreview* preview)
-//{
-//    mutexAcquire(preview->lock);
-//    preview->need_rerender = 1;
-//    mutexRelease(preview->lock);
-//}
-
 //void guiPreviewRedrawAll()
 //{
 //    int i;
diff --git a/gui_qt/preview.h b/gui_qt/preview.h
index b1a6d02..080882a 100644
--- a/gui_qt/preview.h
+++ b/gui_qt/preview.h
@@ -11,13 +11,13 @@ public:
     Preview(QWidget* parent);
     static void startUpdater();
     void doRender();
+    void redraw();
 
 protected:
     void resizeEvent(QResizeEvent* event);
     void paintEvent(QPaintEvent* event);
     virtual QColor getColor(double x, double y) = 0;
 
-private:
     void renderPixbuf();
     void forceRender();