Well the way I see it the "lock" is not really a lock per se, but one of my crewmen keeping the scope centred on the target while I ask the WE for his target solution, go make coffee, and wait for the torpedoes to hit

So the way I see it, it shouldn't lose the lock (despite the waves washing over) because there is supposed to be an "intelligent" officer dedicated to the task. Anyway will just have to live with it!