Summary: Navy Instructional film describing the tugs operated in UK Naval Bases by the Royal Maritime Auxiliary Service (RMAS).
Description: The various classes in use are described, with details of their propulsion, including a description of Voith-Schneider propulsion units, and the uses to which they can be put. The aircraft carrier HMS Invincible (R.05) is shown being assisted in leaving harbour. RFA Olwen (A.122), an unidentified submarine and the County Class destroyer HMS Devonshire (D.02) are shown being cold-moved (without use of the ship's engines).