P-Sea WindPlot, the ultimate chart plotter, can display all position readouts such as Present position, cursor and mark hang list in TD's. They are generated within the program so it works with any GPS or loran. Calibration is simple also, simply drop a calibration point anywhere a TD pair's position is known. Then all TD's in the area are calibrated to that point when in the same area. This is all included with all programs at no extra charge.