b25s were used alot againts ships and dams but at low alt(up to 3000ft) and droped either the HIGHBALL bombs which were round and skipped across the water,and regular ap bombs that they also skipped across the water,the highballs were not very effective so they switched to the reg, ap bombs that did pretty good.
personally i dont see how they were able to skip the reg, ap bombs on the water but somehow they did.