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 an effect similar to the underground detonation of the later Grand Slam and Tallboy earthquake bombs, both of which he also invented.
"Upkeep" bouncing bomb at the Imperial War Museum Duxford
Remains of a Highball test prototype recovered from Reculver in 1997, now at Herne Bay Museum
The Möhne dam breached by Upkeep bombs
Highball bouncing bomb prototype, now on display at Abbotsbury Swannery in Dorset
A depth charge is an anti-submarine warfare (ASW) weapon designed to destroy submarines by detonating in the water near the target and subjecting it to a destructive hydraulic shock. Most depth charges use high explosives with a fuze set to detonate the charge, typically at a specific depth from the surface. Depth charges can be dropped by ships, patrol aircraft and helicopters.
The Mk 101 Lulu was a US nuclear depth bomb operational from 1958 to 1972
Depth charges on USS Cassin Young (DD-793)
Depth charge exploding after being released by HMS Ceylon