Submarine tender

A submarine tender is a type of ship that supplies and supports submarines.Submarines are relatively small compared to most oceangoing vessels, and generally do not have the ability to carry large amounts of food, fuel, torpedoes, and other supplies, nor to carry a full array of maintenance equipment and personnel. The tender carries all these, and periodically meets up with a submarine at sea to replenish it. In some navies the tenders were equipped with workshops for maintenance and as floating dormitories with relief crews.
See more at Wikipedia.org...