Originally Posted by Polwart
Have you tried this? With 1/2 a ton+ of boat I don't fancy trying to stop it if it "runs" away.
Depends how you thread the rope onto your figure of eight.
It can be done in such a way that you have a Munter Hitch (also known as an Italian Hitch) on the figure of eight... which creates a huge amount of friction and makes it very very easy to control a very large weight.
Even if you just go for the straight-forward figure-of-eight, if things can get out of control, it can very easily be dumped off the figure-of-eight into a larks head which will stop everything dead... or alternatively, shock-load the system and snap the rope!!!
If it's really that heavy, then a friction plate can be added, there are lots of things that can be done with enough rope. Could even quickly rig up a 3:1 "Z-rig " or "Pig Rig" to lower it down. You'd need to buy a few carabiners, or better still a pulley - but it would be cheaper than an electric winch.