So, just askin'. Are you planning to work with one of the established hull cleaning firms in your area, or are you going to hang out your shingle and compete with them. What do you know about hull cleaning? What does your toolbox look like? I use an ablative paint on my boat, it takes 8-10 hours to clean it when we haven't gotten underway for a couple of months. It's copper paint on an aluminum boat. If you scratch the paint through the primer, the paint will eat a hole in the boat. If you scrape off all of my ablative paint, you've just ruined a $10,000 paint job. If you gouge my transducers, you've just destroyed a $5,000 or a $25,000 one.
Cleaning hulls is not for the neophyte, especially if you're going to do it for a living. There are many outstanding hull cleaners on this site, many of whom will give you hints and thoughts on how to do the job without pissing off the boat owner. I'd be looking for an apprenticeship before I jumped in with both feet.