Real submariners said that ordering full rudder at high speed in a submarine would make it lose 2/3 of the speed (and some mess on board too) and they use very gentle steer deflections on high speeds. So it's quite OK. Only subs could turn better with low steer deflections, if they only turned so easy like FFG... On the other hand people says the FFG should behave like do subs now, so seems that subs/FFG turning performance and behaviour should be switched :-)
P.S. Sorry Molon, I see it now, the Seawolf really becomes to move backwards after bleeding all speed