Sotheby was aboard "Alexander" during the blockade of Malta and received a share of the prize money for his part in the chase and eventual capture of the French ships "Genereux" and "Ville de Marseilles" on 18 February 1800. At dawn, "Alexander" was to the south-east of the island when her lookouts sighted a French convoy sailing along the Maltese coast towards Valletta. She immediately gave chase and was soon joined by three more British ships. At 08:00, "Alexander" overhauled the armed transport "Ville de Marseille", compelling her to surrender. The other smaller vessels made out to sea but "Généreux" was unable to follow without coming into conflict with "Alexander". She instead bore up at 13:30, and held her position in order to protect her fleeing compatriots. She was engaged by a British frigate and when two other ships came within range at 16:30, she struck. Sotheby served ash/ore as aide-de-camp to Ball during the siege of Fort Saint Elmo and for a while after the island surrendered in September.