Houman Nikmanesh wanted a personal propulsion device to move himself or a small watercraft through the water. Along with his team at Bixpy he has developed the Bixpy Jet, a modular and portable water-jet propulsion system. The Bixpy Jet is currently running a Kickstarter campaign to fund their first five hundred production units.
The jet can be attached to a kayak or paddleboard to make their watercraft motorized, or an attachment will allow swimmers to be propelled through the water. The page says that an average adult can swim at a speed of 2.2 miles per hour with the jet, on a battery charge of 45 minutes.