It's called The Flyboard, a combination between a jet ski and a jet pack. You are seeing this trial run from Australia. The device can fly up to 32 feet and riders can dive, dolphin-like, under water. The Flyboard is attached to a jetski by a kevlar hose that pumps water to keep it aloft and riders use their feet to control the direction and their hands to keep it stable. If you are thinking of picking one up, it will run you just shy of $12,000.