The Sea Fencibles fleet consisted of small vessels such as colliers and coasting vessels such as hoys adapted to serve as gunboats. A hoy was a small sloop-rigged coasting ship or a heavy barge used for freight, usually with a burthen of about 60 tons. English hoys plied a trade between London and the north Kent coast that enabled middle class Londoners to escape the city for the more rural air of Margate, for example. Others sailed between London and Southampton. These were known as Margate or Southampton hoys and one could hail them from the shore to pick up goods and passengers. Concern about a possible French invasion led the Royal Navy on 28 September 1804 to arm 16 hoys at Margate for the defense of the coast. The Navy manned each hoy with a captain and nine men from the Sea Fencibles.
In early 1806, Joseph Ashmore was working on a hoy named the Friends Good Will. He was possibly carrying out duties as a sea fencible when, on the evening of Sunday April 6, the Friends Good Will was anchored in The Downs, a stretch of sea off the coast of Deal in Kent. Joseph and another sailor were endeavouring to get up what is called a fender, a kind of safeguard usually placed at the side of a vessel to prevent damage from another lying alongside, when Joseph unfortunately fell overboard, and was drowned. According to a newspaper report: “Immediately the deceased fell into the water, a rope was handed him from the deck, which he did not perceive, being probably senseless, from a violent contusion on the forehead, which he received from the side of the vessel in his fall. A few minutes only elapsed, before one of the crew caught hold of him just as he was sinking, got him into a boat alive, and had recourse to the usual method of placing him upon a cask for the purpose of recovering him, but all endeavours proved unavailing, as he very soon expired.” Joseph was buried in Dover a few days later leaving his wife a widow and their four children without a father.