World War One. Location of events unknown.
Shot of a submarine moving along surface of sea. Nationality uncertain.
A one-man submarine is tried out on a lake.
Submarine 'Sunfish' rests in port after successful actions under command of Lieutenant Colvin.
British submarines visit Lisbon harbour; their Commander goes ashore.
Sailors go through training to become members of the Submarine Corps.
Cuts (out takes, rushes) for SALVAGE ATTEMPT FAILS in G 1310.
Men practising escape from 'A' class submarine.
Testing submarine by inventor Vassena.
Footage of miniature sub.