Wiktionary
n. A naval mine attached to its target by magnets.
Wikipedia
A limpet mine is a type of naval mine attached to a target by magnets. It is so named because of its superficial similarity to the limpet, a type of sea snail that clings tightly to rocks or other hard surfaces.
A swimmer or diver may attach the mine, which is usually designed with hollow compartments to give the mine only slight negative buoyancy, making it easier to handle underwater.
Usually limpet mines are set off by a time fuse. They may also have an anti-handling device, making the mine explode if removed from the hull by enemy divers or by explosions. Sometimes the limpet mine was fitted with a small turbine which would detonate the mine after the ship had sailed a certain distance, so that it was likely to sink in navigable channels or deep water out of reach of easy salvage and making it harder to find what caused the sinking.
Usage examples of "limpet mine".
The little limpet mine would have a trigger and a timing device and there would be careful instruction on how to set it.
In a whisper, he had told the girl of the limpet mine against the side of the ship timed to explode a few minutes after six o'clock and he had explained the factors that would decide who would die that morning.
A shaped-charge cobalt limpet mine, something the team had been saving ever since the raid on Colonel Wolff's goodies warehouse.
There was only one limpet mine, and Lancer was placing that to the best advantage.
Osman tried to double-cross us, have someone carry a limpet mine aboard.
After all, they had vacationed with Pasha in Saint-Tropez when a limpet mine was discovered on his Jet Ski.
O'Neal had accomplished this last feat by the simple expedient of flying his command suit up to the ship and detonating an improvised antimatter limpet mine by hand.
The course change placed Mike's suit slightly around the corner from the antimatter limpet mine and above it when it detonated.
The limpet mine attached to its side tore a hole down to the combustion chamber, and the buzz bomb lurched to the side and went spinning endlessly down, trailing flame and smoke.