I stripped the bottom paint off a previous boat, a 31' Island Packet. I used "Peel Away". Lay it on thick, cover with their special paper (or plastic sheeting) to seal from air, let it sit overnight, and start peeling it off with a joint compound knife. The bulk of the paint should come off with the first coat, but several coats may be required. It is messy. You need to lay down plastic tarps on the ground to catch the crap as you scrape it off. After striping, washing, and a light sanding, I applied a barrier coat. Probably the cheapest alternative for hull striping, over sanding, soda blasting, et al. Definitely a "do-it-yourself" option. I did one side one year, the other side the following year.