“Napoleon's main mistake at sea was to appoint a man that was no match for those he faced. The French admiral at Trafalgar was a fickle, indecisive man, nothing compared to the energetic and intelligent Nelson”.
Napoleon inherited a fleet from the French Revolution where the political allegiance was the priority, not the professional skills. Louis the XVI fleet was good enough to inflict several defeats to the English but most the Naval Officers were either decapitated or fled as emigrants. If Napoleon would have naval officer like Suffren (who was as much aggressive as Nelson, (see his campaign in India during the US Independence War) or d’Estain perhaps the future of Europe could have been different. In fact, not really. It wasn’t the English Fleet which defeated Napoleon, but the never-ended alliances against him (7). It was the politic of the British Prime Minister (William Pitt) followed by his successors in creating more enemies for Napoleon he could afford.
Napoleon was aware of the weakness of the French Fleet and on the instigation of Privateer like Surcouf favoured the “guerre de course”.