During World War IIOperation Gambit was a sub-plan of Operation Neptune, the naval portion of the invasion of northern France (Overlord). Gambit involved two midget submarines which marked the extreme left and right limits of the British and Canadian invasion beaches with navigation lights and flags.
... point, but the gyro will also be accelerated to a smaller extent by the slipping friction.
The device is covered by US patents 3,726,146 (1973) and 5,353,655 ...