The French commander, Commodore Pierre Roch Jurien, anchored his squadron under the batteries which protected the town of Les Sables-d'Olonne in the hope of dissuading an attack.

In late 1808, the French learned that invasion was planned of Martinique and orders were sent to Willaumez to concentrate with the squadrons from Lorient and Rochefort and reinforce the island.

Beresford turned away to the northwest, and his objective achieved, Gourdan rejoined Willaumez and the fleet sailed inshore, anchoring near the island of Groix, with the route to Lorient clear.

[5] Early on 23 February Willaumez sailed again, taking his fleet southwards towards the Pertuis d'Antioche near Rochefort after sending the schooner Magpye into Lorient with orders for Troude to follow him to the rendezvous.

[8] Stopford had been stationed off the Chassiron lighthouse when Willaumez had passed, and he had sent the frigate HMS Naiad under Captain Thomas Dundas north to notify the rest of the British Channel Fleet that was in pursuit.

[10] At 09:10 Amelia was in range to fire on Cybèle's stern before the British frigate dropped back to join Stopford's rapidly advancing force.

[7] At about this time Caesar withdrew to deeper water to avoid grounding and Defiance veered anchor cable to turn its fire onto Calypso.

[10] Within minutes Calypso had also veered its cable so that Italienne, now beached, could resume fire on the British squadron, but the frigate overcompensated and drifted stern-first onto the shore.

[18] Willaumez had been replaced in March by Zacharie Allemand,[19] whose defensive positions were unable to prevent a major attack by fireships on 11 April followed by a bombardment by conventional warships.

[20] In the aftermath of the battle Gambier was accused of failing to effectively support the attack and faced a court-martial in July, although he was acquitted and returned to command.