I'm with Paul on this one - I used something similar on my '46 Coupe (although it was a gravity feed, not a pressure feed) and it would take off a stripe of, maybe, 1/4"-3/8" at a time. Not exactly time efficient, especially for a boat hull. I would think a good, safe chemical stripper would be far more efficient for your boat.
Another thing to remember is that these typically take a continuous volume of air. Unless you've got a dual-cylinder air compressor capable of LOTS of continuous CFM, you'll blast for a few minutes, then have to wait while the compressor catches up, then blast for another few minutes. The listed consumption of 7 cfm sounds a tad low (probably because it's a pressure feed) but it still is continuous and you'll need a compressor that can keep up.
When I did my Speedster bits, I used someone else's blast booth with either soda or glass beads. It was coupled to a HUGE compressor on a 200 gallon tank and you could blast away continuously - big difference.
gn