A
bouncing bomb is a bomb designed to bounce to a target across water in a calculated manner to avoid obstacles such as
torpedo nets, and to allow both the bomb's speed on arrival at the target and the timing of its detonation to be pre-determined, in a similar fashion to a regular naval
depth charge. The inventor of the first such bomb was the British engineer
Barnes Wallis, whose "Upkeep" bouncing bomb was used in the
RAF's
Operation Chastise of May 1943 to bounce into German dams and explode underwater, with effect similar to the underground detonation of the
Grand Slam and
Tallboy earthquake bombs, both of which he also invented.