This is a special ship attachment that can be added to larger ships.
Rope reel is a pulley mechanism that will be located on one side of the ship. It will have multiple different functions.
Function 1:
The player can take a rope with a hook attached with them as they dive down into the sea. This hook can be attached to sealed chests in order to reel them back to the boat. The player can have up towards 2 hooks at once. This will save time on trips underwater.
Function 2:
The player can wrap the rope around themselves and will be able reel themselves back up towards their boat in the case of low stamina, running out of oxygen or getting lost.
Function 3:
Rope reels that are attached to the back of a ship can be used to tow other boats. This cna be used to tow damaged boats to help out friends. The connection can be broken if attacked directly.
Function 4:
Can be attached to other players as punishment and drag then accross the sea for disturbing your cargo runs
The addition of rope reel will open the doors to a new sea acitvity which will require the player to tow stranded ships towards a nearby city for rewards.
Possibly with the advantage that the chest will go directly to the ship and being able to take a sealed chest on hook and one on your hand at the same time
I assume the last one is a joke, but all of these ideas are good. I would add that the rope reel should be able to pull lost cargo and maybe castaway rafts towards you.