Trinity House ship sets out from Harwich to clean and replace fuel of buoys at sea.
Several shots of buoys at a warehouse on the quay. Various shots show the Trinity House Vessel 'Siren' setting out to sea to carry out maintenance on buoys; a naval flag showing the Union Jack and the Trinity House Jack is hoisted; officers are seen using sextants and plotting their course on a chart. Nice M/S of a sailor tying on a life jacket. Sailors drop anchor beside a buoy, hoist weather balloons and ring bells on the ship.
The buoy is cleaned of mussels and limpets on the base, fitted with a new gas cylinder to power the flashing light and lowered back into the sea. The sea crustaceans are thrown back into the water.
Cuts exist - see separate record.