The one Italian strength that concerned the Allies was the Italian Royal Navy ("Regia Marina"), the fourth-largest navy in the world at the time. In November 1940, the British Royal Navy launched a surprise air attack on the Italian fleet at Taranto which crippled Italy's major warships. Although the Italian fleet did not inflict serious damage as was feared, it did keep significant British Commonwealth naval forces in the Mediterranean Sea. This fleet needed to fight the Italian fleet to keep British Commonwealth forces in Egypt and the Middle East from being cut off from Britain. In 1941 on the Italian-controlled island of Kastelorizo, off of the coast of Turkey, Italian forces succeeded in repelling British and Australian forces attempting to occupy the island during Operation Abstention. In December 1941, a covert attack by Italian forces took place in Alexandria, Egypt, in which Italian divers attached explosives to British warships resulting in two British battleships being severely damaged. This was known as the Raid on Alexandria. In 1942, the Italian navy inflicted a serious blow to a British convoy fleet attempting to reach Malta during Operation Harpoon, sinking multiple British vessels. Over time, the Allied navies inflicted serious damage to the Italian fleet, and ruined Italy's one advantage to Germany.