It's an easy route to go if you're only looking to get a little umph of the lower frequencies, but it will not increase the bottom end drastically. I know of someone who was pretty impressed with one under the bow of an 18ft jet, but I'm not wure how well it will perform in a much larger open boat. I hear that the Infinity powered sub does a bit better. I think RiverCrazy has one in his Tundra. You may want to PM him for more info thoughts on preformance in a boat.
You'll get a lot more out of a small sub amp(250wwatts) and 1 good sub vs the powered Bazooka....
You really need to know what kind of sub performance you're looking to achieve before you commit yourself to your purchase...