Bestbuy offers Sublue - WhiteShark Mix Underwater Scooter - Aqua Blue for $399.99 (orig. $549.99) +Free Shipping.

Product Description:

Take your swimming to the next level with this Sublue underwater scooter. Attach your action camera to the mount, and capture sublime aquatic videos while you experience professional swimming speeds and depths of up to 131 feet. This Sublue underwater scooter has a portable design, so you can easily bring it wherever you go.
Portable underwater scooter; dual motors provide up to 3.35 mph top speed; dive depth up to 131'; detachable floater; rechargeable lithium battery provides up to 30 minutes of run time; mount for camera