A phrase of
Navy jargon used by
submariners to describe a
sub when it is not moving and is
rigged for silent running.
This means that there is nothing running on the boat that is not needed. Laundry, ventilation, galley, showers, everything is turned off (except the coffee maker when operating under silent running for long periods of time). The crew wears soft-sole shoes or padded shoe covers. Pretty much the only things on are the reactor and coolant pumps. Remember the shaft is not turning because the boat is stopped. Many times the captain will bottom the boat to avoid active sonar detection.