Not good for a watercraft. A vertical cross section is hardle efficient for going horozontally. A battery powered paddleboard with neutral bouyancy, internal water jets and some movable internal weights would be far more efficient. You could also add a cowling and some cross bars as shark protection.
I am not sure if they make the bubble on top supplied with air from a tank with a small % over feed, as I see no bubbles or mask.
A good aspcet is the low weight and high air bubble will keep it vertical, but if you lose the bubble, you sink, so you may have potential buoyancy problems