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://github.com/ArcGIS/arcgis-pro-sdk/blob/master/Images/waterAnimation.gif)
/// </summary>
/// <returns></returns>
private static Task<CIMPolygonSymbol> CreateWaterFillPolygonAsync()
{
  return QueuedTask.Run<CIMPolygonSymbol>(() =>
  {
    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
      };
    return new CIMPolygonSymbol() { SymbolLayers = symbolLayers.ToArray() };
  });
}