bottom paint removal -best electric vacum sander?

[McGillicuddy]

$1200 seems kind of proud for a soda blast. Must be using diamonds
Fein is probably the best sander of this type in the industry - actually air driven by the vacuum, I think. Same people that brought us the Multimaster.

But I'm with Tucker on that. Use a stripper, any gel MARINE stripper ($20/gal. or so) will work especially if the paint is thin. Most of the decent "green" strippers are $60 /gal. or more. Do a bit at a time on the shady side or cooler time of day. 3'x3' or so at a time. Paint bubbles up and skim it off with a 3" putty knife. Get the balance with a very fine steel wool and paint thinner or may lacquer thinner if the paint thinner is ineffective.

Soy stripper has excellent reviews but is pricey. I would probably avoid citrus based stuff, at least I've never had great results with it...Methyl chloride, baby... I do a lot of kitchen and bath remodels and haven't sanded a finish off for years, touch up yes, but 23 ft. boat - no way! Wear heavy duty chemical resistant gloves, long pants and sleeves, and safety glasses; and keep the gel off of your skin and eyes (burns like a mother). Use a respirator with organic/solvent filters - about 30 bucks w/filters at home improvement stores.

Good luck.