my suggestion is something along the lines of a bunch of friends can operate a ships sails, repairs, cannons etc could even have cool reloading mechanics requiring loading the powder, cannonball etc. and you can fight other crews etc in an open world of sorts, all islands and treasure to explore and plunder and like you could even have reputation where the more treasure you find and take, the higher your bounty and stuff and yeah like become notorious and stuff, something along this, could be cool and because the captain role would be highly wanted maybe rotate it between battles or something or could just have two options when you join, either join the game as a captain or as a crew member with a certain amount of captains allowed on a server until its full and you can only choose to get crewmember