I have some ideas based on an Age of Sail game, but it gets a bit tricky if a lighter ship rams a larger one. There are some historical moments of friendlys getting together, and even DDs can do some damage to BCs if the situation is right. Obviously if a BC or BB can catch a DD, it should be multiple damage dice based on the difference in class, followed by critical hits on the hull and crew table. Also, the lighter ship will turn to conform with the direction of travel of the larger ship. Afraid I dont have any experience with other WW1/WW2 era games, and can't recall from the modern rules.
Tom Oxley