“Project Seal” was the code name for a secret test operation between the US and New Zealand during the Second World War to test a series of bombs that would create a Tsunami as a weapon.
The series of 10 bombs would create a 33-foot high wave capable of overtaking an entire coastal city. The US let off about 3,700 bombs off the coast of New Zealand during their testing.
Had the atomic bomb not had the success it did, the Tsunami bomb might have taken off with the US military.
A New Zealand filmmaker discovered details of this secret mission while he was digging through the national archives, now it's public.