Note also that line of sight can never be drawn through an enemy ship. For game purposes, consider any attempt to hit a ship that is past a nearer ship is not a possibility (due not only to whether the farther ship can be seen - which is possible - but that its range is impossible to judge with respect to movement of the attackers' ship, the targeted ship and the ship in between the two ships. Therefore, we dispense with that situation and accept that ships can 'hide' behind other ships.
Furthermore, targets cannot be fired at through land hexes or destroyed hulks either.
See Naval Warfare