CIMFill ConstructWaterFill( 
   CIMColor color,
   WaterbodySize waterBodySize,
   WaveStrength waveStrength
)

/// <summary>
/// Constructs a water fill of specific color, waterbody size and wave strength. This fill can be used on polygon feature classes in a Scene view only.
/// ![ConstructWaterFill](https://ArcGIS.github.io/arcgis-pro-sdk/images/Symbology/waterAnimation.gif)
/// </summary>
{
  //Note: Run withing QueuedTask

  CIMStroke outline = SymbolFactory.Instance.ConstructStroke(CIMColor.CreateRGBColor(49, 49, 49, 50.0), 2.0, SimpleLineStyle.Solid);
  var waterFill = SymbolFactory.Instance.ConstructWaterFill(CIMColor.CreateRGBColor(3, 223, 252), WaterbodySize.Large, WaveStrength.Rippled);
  List<CIMSymbolLayer> symbolLayers = new List<CIMSymbolLayer>
    {
              outline,
              waterFill
    };
  CIMPolygonSymbol waterFillPolygonSymbol = new CIMPolygonSymbol() { SymbolLayers = symbolLayers.ToArray() };
  //To apply the symbol to a polygon feature layer
  //var renderer = theLayer.GetRenderer() as CIMSimpleRenderer;
  //renderer.Symbol = waterFillPolygonSymbol.MakeSymbolReference();
  //theLayer.SetRenderer(renderer);
}