The Stingray developed by Sandia National Laboratories and TEAM Technologies is not the water gun you had as a kid... it has a 'bit' more power.
...it uses an ultra-high-pressure water beam to slice through steel, ripping bombs open before they can harm troops. The Stingray involves a clear plastic water tank, about the size of a coffee pot, attached to an explosive charge. The detonation creates a shock wave that propels water toward a concave opening in the reservoir, which shapes the water into a blade. The device works at short range and over long distances, according to Sandia Labs....watch video demo below.