Last year my son built and tested something similar, but with the battery box built into the board. It proved the concept, but definitely not something I ever want to ride again until we get a small jet drive or two also inside the board. Falling off in a wave was quite scary with that big heavy chunk of steel hanging off the bottom. Maybe fun on a lake or with outriggers and avoiding the surf.
Bottom line is that you want to pass on this one, unless it's cheap enough to use as a base for your own mods. That board isn't thick enough near the rear to contain a motor and drive unit though. Ideally a good starting point would be longboard blank or one of those standup paddleboards.
John
