Wow, enemy naval units frustrate me more after they have been destroyed. Like land units, the husks of destroyed naval units can be destroyed by direct fire. Usually I just ignore destroyed units until I have a chance to use "reclaim." This is no problem on land because land units manuever much better; however, every obstacle is important for naval units. The presense of destroyed naval units on the ocean surface causes my navy to behave erratically. This problem would be solved if destroyed naval units sunk to the ocean floor. Also it would be cool.
Brian's suggested the quite a bit, but for now wrecks altogether will be removed for future implementation. Wrecks were too much of a hassle for pathing and Uber's decided to sit on it for a while until they can come up with a complete answer to the problem.