All three ships served during World War I providing training for crews and officers on the U.S. East Coast, before the class was decommissioned and sold for scrap in 1922.

[1] For surface running, they were powered by two 300-brake-horsepower (224 kW) NELSECO gasoline engines, each driving one propeller shaft.

D-3 was fitted with only two bulkheads leaving one large compartment in the middle that consisted of both battery wells and the control room.

[4] On D-1 and D-2 the helm wheel was actually in the after battery compartment, as the placement of the aft control room bulkhead dictated this arrangement.

[5] Many future Admirals commanded a D-class submarine early in their careers including Chester William Nimitz[6]