Hello Terry,
I agree with you quoting that there is virtually no steerage in reverse, although surely not for all ships with standard rudder/propeller arrangement.
There are fishing vessels, seagoing tugs, pilot ships that can be manoeuvered in reverse, although only when there is not too much wind, and by skillfull captains. Like you mention, sailing yachts and historical yachts too.
Foreseeing movement and track of a such ships when reversing and then backing is certainly difficult. The pivot point (center of giration) of the ship moves to the stern, reducing an already weak turning moment, while setting too great rudder angles, stalls the rudder now taken aback.
Nevertheless, as once there is a distinct flow of water on the rudder, the side thrust exerted by the rudder is the same as when going ahead engine stopped, for any practical use. The resulting turning moment is of course different, and will probably not counterbalance the transverse thrust effect of the propeller if needed. To gain speed backwards, you cannot evidently do without some propeller...
So, there is a definite effect, that can and must be simulated or computed, but its direction and the resulting turning moment are so uncertain that most people think it is unpredictable. Yet, all ships turn readily when backing, very often even too much, and not in the desired direction. And is that not in fact the problem?
The simulation of such characteristics (rudder thrust, its lift and drag as a function of speed of ship and of propeller rotation, propeller thrust components) can make a realistic simulation, much more than neglecting existing forces, I think.
About the list, could you please tell me which ships aren't in it, so that they could be added?
Regards,
Luc
