The Sea Fencibles (from ‘defensible’), were a naval equivalent of the Home Guard formed during the Napoleonic wars. They were formed in May 1798, at a time when there was a very real threat of an invasion from France. At first, their duties were on land. They were trained in the use of the cannon and pike, and it was hoped they would provide some of the men needed for the line of Martello towers being built along the south coast. They were also employed in helping the naval signal stations, and with the revenue service. This would appear to have been somewhat ironic, as it was a common complaint that many of the sea fencibles were themselves smugglers! Eventually, the sea fencibles were given their own small boats, with which they were expected to attack any French invasion barges as they approached the beaches.
The Sea Fencibles were recruited from volunteers in coastal areas. It paid 1s per day, but the main incentive was immunity from service in both the militia and from the press gang. Unsurprisingly, there was no problem getting volunteers. There was also no shortage of potential officers. The Royal Navy produced more officers than it could easily use, especially with no concept of retirement. This meant that there was a ready supply of lieutenants, used to command the fencibles in individual towns, and captains, who commanded entire districts.
Naval opinion was split over the usefulness of the fencibles. Captain Schomberg, commanding the Dungeness Fencibles, considered his men to be smugglers and wreckers. In fact, many were fishermen or bargemen, including some who normally worked on the rivers. In contrast, Lord Nelson, who had command of a force of sea fencibles when he had command of the coastal defences, thought that they could play an important role if the invasion came.
The sea fencibles were disbanded during the Peace of Amiens. In 1803, they were reformed, but only after the press gang had had its chance to fill the navy. They did take part in some minor skirmishes with the French, although their lack of larger ships limited their potential. After 1803, the sea fencibles were given a more important role at sea. Whenever there was an invasion scare, two lines of blockade were formed – one off the French coast, provided by the navy, and one off the British coast, mostly provided by the sea fencibles, using smaller gunboats.
As the war went on, it became increasingly clear that the risk of a French invasion was over. At the same time, the number of men involved was rising, reaching a peak of 23,455 men in 1810. By this point, their original purpose was clearly over, and the same year saw the sea fencibles disbanded.