Film intended to show ships of the Royal Navy training for their operational role in defending British interests at sea.
After a compilation of scenes showing British warships around the world the film goes on to illustrate anti-submarine warfare methods, including the firing of an Ikara missile by the Leander Class frigate HMS Leander (F.109), the firing of anti-submarine mortars by a Leander Class frigate and the engagement of a hostile submarine by a Wasp helicopter launched from the Leander Class frigate HMS Danae (F.47). A flotilla deployed to the Pacific is shown conducting a replenishment at sea with a total of seven ships in line abreast formation, centred on the Royal Fleet Auxiliary vessels RFA Tidespring (A.75) and RFA Tarbatness (A.345). HMS Danae prepares to refuel from astern of RFA Tidespring and then makes her approach. The County Class destroyer HMS Fife (D.20) disengages from the centre of the replenishment formation and proceeds on her own to carry out a gunnery exercise. The ships are shown briefly arriving in Auckland, New Zealand and Sydney, Australia, and sailors appear on shore in New Zealand as they experience some local culture. A naval officer is interviewed on the Sea Slug surface to air missile system, and his description of the missile is accompanied by scenes showing the loading and firing of Sea Slug from a ship at sea. Royal Marines are shown deploying in northern Norway from Wessex helicopters and crossing the country on skis. A Polaris missile firing is shown as a reminder of the Navy's possession of strategic nuclear weapons, and the film ends with a brief look at future warships. The aircraft carrier HMS Invincible (R.05) is shown under construction at Barrow-in-Furness, the new Type 42 destroyer HMS Sheffield (D.80), later lost during the Falklands War, and the new Type 21 frigate HMS Amazon (F.169) are shown at sea and finally a formation of seventeen ships is shown manoeuvring together.