The British anti-shipping campaign suffered greatly by the end of March 1942

A combination of events created a lack of forces to pursue an active campaign against Axis shipping. By the end of March 1942, the situation had reached a crisis. The blows came often and fast. After December 8, warships, troops, and aircraft had to be sent to the Far East to combat the Japanese attack. Then the battleships Queen Elizabeth and Valiant were damaged in Alexandria harbour by brave Italian under water demolition specialists. The increased German air and submarine presence further aggravated the British situation, as the British took heavy losses in surface warships to aircraft, mine, and submarine attack. We can't forget the loss of the Ark Royal, very close to Gibraltar. By the end of March, the Mediterranean Fleet was reduced to four cruisers and fifteen destroyers. The low point was reached with there were only six destroyers able to put to sea. The British had hoped that increased air power would compensate for the reduced surface force, but then Rommel retook western Cyrenaica, so they lost the airfields that would made the air forces more effective. This is based on the account in Vol.III of the Official History.