This film is part of Free

Sea Fort

Surrounded by water and manned to defend the coastline, sea forts were remote outposts of Britain’s home front.

War 1940 7 mins

From the collection of:

Logo for Imperial War Museums


Sea forts were observation and gun fortifications used to help defend Britain during the Second World War. They were also temporary homes for the various crews that were stationed there. This short propaganda film glimpses their day-to-day lives aboard one of these unusual outposts, alongside the naval guns and searchlights, ready to scour the night sky for enemy aircraft.

Also known as Maunsell Forts, some of these unusual structures were mounted on long concrete legs, or even linked together by steel bridges. They were occupied by both British Army and Navy personnel and had two primary functions; to prevent aircraft from laying mines and to help defend against Luftwaffe bombing raids. This government film is a public record, preserved and presented by the BFI National Archive on behalf of The National Archives, home to more than 1,000 years of British history.