The Bayonnaise was a French 24-gun corvette, launched in 1793. Ship-rigged (i.e. with three masts), of 580 tons and 125-ft. length, she was armed with 24 eight-pounders and four light “obusier”. The latter were short-barrelled, close-range weapons, the French answer to the British carronade, and of use only when ships were lying close together, ideally hull-to-hull. Her normal crew was about 220. Designed originally as a privateer, she was taken on the French Navy while still on the stocks. Her light armament fitted her well for a privateering, commerce-raiding role, but was likely to put her at a severe disadvantage if she encountered any larger vessel.
HMS Ambuscade was, by contrast, much more powerful, a 32-gun frigate which had seen successful service against the French in the American Revolutionary War. Though her dimensions were generally similar to the Bayonnaise , and though she carried a similarly sized crew, her armament was considerably heavier – 26 twelve-pounders, a total of eight six-pounder bow and stern chasers, four eighteen-pounder carronades on the quarterdeck and two on the forecastle. In any ship-to-ship action between the two vessels the Bayonnaise might have been expected to have little chance of survival.
From August 1798, at a time when the Royal Navy’s blockade of the French coast was becoming ever more effective, HMS Ambuscade, commanded by Captain Henry Jenkins, was ordered to patrol off the French Atlantic coast. At dawn on 14th December, when she was cruising off the Gironde estuary, and expecting to meet HMS Stag, she sighted a sail. Assuming this to be the Stag, she steered closer. The newcomer was in fact the Bayonnaise which, significantly as it later proved, was carrying a 40-man army detachment in addition to her own crew. The French ship, recognising that she was outsized and out-gunned, went about and fled. A stern-chase ensured and it was not until noon that the range closed sufficiently for the first shots to be fired.
The action might have ended when HMS Ambuscade crossed Bayonnaise’s stern. This was the most vulnerable part of any sailing man-of-war, as shot crashing through the stern could run longitudinally along the entire inner decks, destroying all in their path. The manoeuvre, if successfully executed, was the deciding factor in many naval battles. It was at this moment of greatest risk that Bayonnaise’s luck kicked in. One of HMS Ambuscade’s 12-pounders burst, killing thirteen around it and destroying the vessel’s boats. In the ensuing confusion Bayonnaise headed south and a new stern chase developed. HMS Ambuscade, recovered from her set-back, drew level in mid-afternoon – when on this winter’s day only a few hours of daylight still remained.