Schleichfahrt is german and means 'to drive very slow'
Intentionally it's used in submarines to hinder being detected by other vessels.

There is also a computer game called 'Schleichfahrt'.
It is settled in a apocalyptic future, where, after a nuclear war, the whole surface of earth is radiated, so man had to descend into deep water.
The player slips into the role of Eryn 'Dead-Eye' Flint, the best pilot, that was sabotaged in his last mission and therefore spoilt it.
He had to prove he is the best once again by acheiving various missions, from standard escort to asassination missions, also some under-cover missions.
The great show-down is a fight against the mutants, an evil, artificial intelligence lifeforms that pilot impressive ships with severe firepower, that are of course extinguished by the player in the end.