face it, not much sea fighting back in the day when they used swords and maces. not too mention all the orcish hordes they had running around.
boat battles where faught by having one boat get close to another, then having regular sword battles with those on the boats. or possibly someone throwing a flaming stick on another boat. it wasn't important, and it wouldn't be much fun.
the real question is,.... are we gonna have those hot air ballons that the orcs used??