I've found it a little strange, being in the open world, having the ships' cannons out all the time, and those ports going under water, What I find strangest is that the ports are open. When traveling, most ships closed the gun ports and kept the guns hidden on the inside of the ship.
If you ever implement the gun ports being closed, you could also add an animation at the beginning of a battle of the gun ports opening and the cannons being pushed out.