I think it would be cool to have a tdm game mode without ships and just fighting on an island. People already do this in arena but its harder to do now because the time has been reduced. However I think it would be much more fun if more people were fighting... ill give an example:
say they're are 4 crews (can be duos or even ffa).Time limit of a match is 10 to 15 minutes. Everyone spawns on an island in random locations. Preferably a medium to bigger sized island depending on the number of people. It can use the point system that is currently in arena to keep score. Say 5 points per kill. each time you die you come back with full ammo and 5 Pomegranates. They could even have a option to change your load out of weapons before spawning, so if you wanted to switch to a sniper in stead of a pistol you can do that... If you run out of ammo you can get ammo and crates around the map or even make it to where each kill gives you 1 bullet.. or you generate 1 bullet for the gun that you have out in your hand every 10 seconds (lots of ways to balance this).... for food I don't know. You can get food from barrels. If food regenerated some people can just live forever which prolly isn't good.
I think there could be even other versions of TDM like collect bounties. say every time you kill someone you can pick up a bounty on their body and to confirm the point you have to bring it to a turn in station. But if you die you drop them all and the next person can take all the bounties to the station. Who ever with the most bounties at the end of the time limit wins.
Another version could be capture the flag. with 2 teams against eachother. idk I think that this could be a new awesome game mode that could get people better at PvP while having fun. New commendations could be unlocked as well as weapons skins like the legendary sea dog weapons... maybe an all black weapon set with white skull and cross bones on it... what do you guys think. Im just spit balling