The gunboat was the smallest class of warship in use during the Napoleonic wars. The basic definition of a gunboat was a small warship with at least one heavy gun, normally pointing forward or aft, and that could only be aimed by pointing the entire boat at the target.
Gunboats fell into two main types. The smaller types resembled large ships’ boats, although they were designed to work independently of larger ships. These normally only carried the front and rear guns. They were very useful for coastal defence or for use in shallow waters. Larger gunboats also carried broadside guns, normally ten in number, and had the same sails and rigging as brigs and schooners. They were eventually reclassified as gun brigs or gun schooners.
The small gunboats went through a variety of forms before taking their final form in 1805. These boats, designed by Commissioner Hamilton, varied from 43 to 51 tons, and normally carried three guns – two in the bow and one in the stern, all 18-pounders.
The larger gunboats varied ranged from 146 to 177 tons. The most common type was the Archer class of 1801. Fifty eight of these 177 ton boats were built between 1801 and 1805. They carried a 32-pounder bow gun, while ten 18-pounder carronades formed the broadside.
The smaller gunboats were used by the sea fencibles, a naval ‘home guard’, where they were intended to attack any French invasion barges. They also took part in offensive operations, such as Nelson’s attack on Boulogne, or the Walcheren attack of 1809, where a line of gunboats was intended to row ahead of the troop boats, to destroy any resistance on the beaches.
Gunboats were also used to escort convoys around the British coast. Each port had its own gunboat, which was used to escort any convoy to the next port, where it was handed on to the next gunboat. This was a response to the threat of French privateers.