Why did Horatio Nelson have difficulty finding the French fleet before the Battle of the Nile?

Horatio Nelson’s difficulty in locating the French fleet before the Battle of the Nile was primarily due to a lack of frigates, which were essential for reconnaissance.1

Earlier, on May 20, 1798, a storm had dismasted Nelson’s flagship, the Vanguard, and caused his group of frigates to become dispersed and return to Gibraltar. Without these scouting vessels, Nelson was unable to effectively track the movements of the French expedition after he discovered that Toulon was empty. Although he correctly guessed that the French were headed for Egypt, he arrived at the port of Alexandria before them and, finding it empty, mistakenly concluded they were elsewhere and returned to Sicily to resupply. He eventually located the French fleet at anchor in Aboukir Bay upon his return to the Egyptian coast on August 1.12