you could modify some servos to rotate continuously and make a cable drum and attach it to the servo, then mount it under the deck.
The chain can then run over the smooth drums.
the only problem I can see is to drop anchor it will have to be lowered instead of dropping.
The aft winch will have to use gearing to prevent it from slipping.
Again using servos mounted under the deck but having the gear cog passing through the deck to mesh with the gears on the winch.
I hope this makes a little sense .