Battle of St . Lucia The Battle of St . Lucia or the Battle of the Cul de Sac was a naval battle fought off the island of St . Lucia in the West Indies during the American War of Independence on 15 December 1778 , between the British Royal Navy and the French Navy . Background . On 7 September 1778 , the French governor of Martinique , the Marquis de Bouille , surprised and captured the British island of Dominica . On 4 November , French Admiral Jean Baptiste Charles Henri Hector Comte d ' Estaing sailed for the West Indies from the port of Boston . On that same day , Commodore William Hotham was dispatched from Sandy Hook , New York , to reinforce the British fleet in the West Indies . Hotham sailed with " five men of war , a bomb vessel , some frigates , and a large convoy . " The convoy Hotham was escorting consisted of 59 transports carrying 5 , 000 British soldiers under Major General Grant . The French fleet was blown off course by a violent storm , preventing it from arriving in the Caribbean ahead of the British . Admiral Samuel Barrington , the British naval commander stationed on the Leeward Islands , joined the newly arrived Commodore Hotham on 10 December at the island of Barbados . Grant ' s men were not permitted to disembark and spent the next several days aboard their transports . Barrington and Hotham sailed for the island of St . Lucia on the morning of 12 December . On the evening of 13 December and morning of 14 December , Major General James Grant , supported by additional troops under Brigadier General William Medows and Brigadier General Robert Prescott , landed at Grand Cul de Sac , St . Lucia . Grant and Prescott took control of the high ground around the bay , while Medows continued on and took Vigie the following morning ( 14 December ) . It was on 14 December that the French fleet under d ’ Estaing arrived , forcing Admiral Barrington to move his ships into line of battle and forego his plan of moving the transports into Carénage Bay . Admiral Barrington had the following ships at his disposal : Admiral d ' Estaing ' s fleet was composed of the following ships : Naval engagement . Admiral Barrington was alerted to the presence of the French fleet by the frigate " Ariadne " . He organised his line of battle such that " Isis " and his three frigates ( " Venus " , " Aurora " , and " Ariadne " ) were close to shore guarding the windward approach , and he placed his flagship , " Prince of Wales " , toward the leeward . Barrington placed his transports inside the bay but behind his battle line . Barrington ’ s defensive strategy took him the entire night of 14 December , and by 1100 hours 15 December , most of the transports had been safely tucked behind his line . At 1100 hours 15 December Admiral d ’ Estaing approached St . Lucia with ten ships of the line , and was fired on by one of the shore batteries . D ’ Estaing then moved to engage Barrington from the rear , and a “ warm conflict ” raged between the two fleets , with the British supported by two shore batteries . D ’ Estaing was repulsed but succeeded in reforming his line of battle . At 1600 hours d ’ Estaing renewed his assault by attacking Barrington ’ s centre with twelve ships of the line . Again , heavy fire was exchanged and the French were eventually repulsed for a second time . Outcome . On 16 December Admiral d ’ Estaing appeared to be preparing for a third assault against Admiral Barrington ’ s line , but then sailed away towards the windward . On the evening of 16 December d ’ Estaing anchored in Gros Islet Bay with " ten frigates and twelve sail of the line , & c . " Admiral d ’ Estaing ’ s failure to break Barrington ’ s line on 15 December spelled doom for the local French garrison , which surrendered on 28 December .