The watersports world has been a little spoiled in the last week with news of the Zapata Flyboard breaking - but even though that one's going to be very tough to top, we thought the Abyss Board was pretty unique and fun in its own right. Towed quite slowly behind a boat, this simple device lets you steer yourself around under the water. With separate control of right and left side wings, you can dive, rise, bank, carve and barrel roll your way through the water. As you're underwater the whole time, you don't need to be going fast to get quite a motion thrill - so in a way the Abyss Board is a reasonably eco-friendly rush. I tell you what though, I wouldn't want either of my brothers at the boat throttle while I was playing with this thing - and they wouldn't want me driving either!