HMS K15 was a K class submarine built by Scotts, Greenock.

K15 sank due to an accident, when moored alongside the light cruiser Canterbury at Portsmouth Harbour on 25 June 1921.

[2] The submarine was powered by two oil-fired Yarrow Shipbuilders boilers each supplying one geared Brown-Curtis or Parsons steam turbine; this developed 10,500 shaft horsepower (7,800 kW) to drive two 7 ft 6 in (2.29 m) screws.

Submerged power came from four electric motors each producing 350 to 360 horsepower (260 to 270 kW).

[2][4] It could operate at a maximum depth of 150 ft (46 m) and travel submerged at 2 kn (3.7 km/h) for 80 nmi (150 km).