never seen a 3speed auto, but we put alot of powerglides in boats. thats a 2speed auto. Look at dirt track supplies for a coupler to use in...
we did this with a harley motor. we did direct drive with a cluth on it from a company called emf. worked great . boat was a 14 flat. only...
I do not kow alot about the coastguard regs. But gfci are required with in 6 feet of running water. Also 12 vdc is alot different than 120 vac....
To anyone who may want to get rid of any molds, I am looking for some. Must be willing to ship to colorado. Thanks Mntfisher