Hear me out,
if there was a station somewhere out on the sea where you could dock your boat, use pulleys to lift it out of the water and clean the bottom of your captained ship to maintain proper speed, turning/radius, it could give some immersion and/or extra difficulty while in battle, or while trying to run away. The dirtier ships covered in barnacles would travel slightly slower, giving other people a chance to catch up to get their loot, forcing people to either sell earlier, or stop and clean their ship. This could happen by staying idle for too long, or by sailing through dirty patches of water, which would also make battle more interesting if you had to keep your eyes out for floating sea weed or barnacles on top of powder kegs in the midst of battle.
To make sure people use this system, you raise the price of the repair at the dock, so that people are enticed to actually using it. while you are Careening your ship you are vulnerable but choosing the time to do so is vital.
i think it would add another step of realism that could be fun as well, im picturing sharks tale, and all the fish working at the carwash... but in this sense its the boat wash, and you and your crew get to scrub the bottom of the boat because shes filthy, ye savvy?
