When the convoy was sighted, its escort outnumbered Kempenfelt's squadron by more than half. Because Guichen's warships were downwind of their charges, the British could use their faster command cycle to maneuver against the transports first. Kempenfelt's captains understood his signal book well enough to act before the escort formed to stop them. The initial rush took fifteen troop-and-supply ships, and the total rose to twenty-one transports and about 1,600 personnel.
Chapter · 22:34-23:42
The 1781 Battle of Ushant: a fast strike on the convoy
With Guichen's escort downwind, Kempenfelt's smaller squadron uses rapid signaling to seize transports before the French warships can intervene.