Spent 3 seasons chunking barnacles with a scraper, then a $30 air chisel in Galveston changed my mind
For the first few years I did hull cleaning with a hand scraper and a wire brush, and my shoulders were wrecked by lunch every single day. Last spring a guy on the dock in Galveston let me borrow his air chisel for one tide cycle, and I knocked out a 40 foot hull in about half the time with way less wear on my body. The scraper still has a place on soft coatings where you don't want to gouge anything, but for heavy barnacle work the chisel wins hands down. Now I keep both on the boat and pick based on what's growing down there, and I'm not looking back. Anybody got a preference between an air chisel and a needle gun for the really crusty stuff?
A $30 air chisel sounds great until you hit a hull with a fresh barrier coat and watch it hop and gouge. I've seen more gelcoat and paint damage from power tools in one season than from hand scrapers in five, and fixing that costs way more than the time you saved. The scraper being slower is kind of the point, it keeps you honest on soft coatings and thin spots.