public override object GetSuffix(string suffixName)
{
if (suffixName == "LAT") return Lat;
if (suffixName == "LNG") return Lng;
if (suffixName == "DISTANCE") return DistanceFrom(Vessel);
if (suffixName == "HEADING") return (double)GetHeadingFromVessel(Vessel);
if (suffixName == "BEARING") return (double)GetBearing(Vessel);
return base.GetSuffix(suffixName);
}