High Quality Content by WIKIPEDIA articles! A submarine tender is a type of ship that supplies and supports submarines. Submarines are 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 either meets up with the submarines at sea to replenish them or provides these services while docked at a port near the area where the submarines are operating. In some navies, the tenders were equipped with workshops for maintenance, and as floating dormitories with relief crews. Unable to operate conventional surface tenders during World War II, the German Navy used Type XIV submarines (milchcows) as tenders instead.