So in the spirit of Warcraft (2) maybe it could be an option to develop a seafaring pvp battleground or a dungeon.
Battlegrounds:
It could be essentially capture the multiple flags, which would control the ships like the graveyards in AV. Each small ship could also be tied to a commander on the Flagship like the bosses in AV. The last ship being a much larger Flagship with a PVE boss battle. The winning cicumstances could be either stopping the other team with a death counter or killing the enemy admiral in thier chambers. The ships could have a couple cannons, and players could load them like in the Stratholme dungeon to stop incomming boardings. And you can have a flight path to the ships you control. With 4 ropes on each ship to assault from the water. The ships could move closer and farther from each other and the capital ships up and down allowing more cannon control options if the ships nearest to them are taken.
OR
Just reimagine the WotLK Carrier V Blimp battle (but into seafaring vessels) as a short PVP scenario. The 2 ships go in and out of range on an animated teadmill loop. Where the player can either use the cannons (maybe add the Strat mechanic of loading the cannons), their own long range moves, or at times swing to the other ship. Defend your Admiral and kill the enemies. If you die, you ressurect on the bottom floor of your ship.
I understand this would be an almost impossible challenge, so I tried to list the systems in the game to use as references. Surely my idea could be expounded upon or mayde better with you own brilliant ideas. It could even be as simple as 2 ships going in an oval animation, and you have to jump over and kill the boss NPC or defend yours.
This could all lead to some new items, transmogs, titles, or faction reps.
Or just a well though out dungeon with a certain pirate group or the other many seafaring factions? Surely our heads combined can create a unique Turtle WoW area with ship combat! <3