I am a boat detailer by trade. D'oh, I know.
You need to get 3M compound, and a high speed buffer. ($23 Chicago tools model) Compound, then wash. You don't need marine soap, especially if you are on land.(marine soap is supposed to be "greener", but I doubt it)
Dawn kitchen soap actually removes any of the wax you may have missed while compounding. It's what I use, and a little goes a long way.
After that, use a marine wax, as they seem to last longer under salty conditions than the non marine waxes. I hope this helps.