While the majority of TF 39 joined the British Home Fleet – being renumbered to TF 99 in the process – to cover convoys routed to North Russia, "Wasp" departed Scapa Flow on 9 April, bound for the Clyde estuary and Greenock, Scotland. On the following day, the carrier sailed up the Clyde River, past the John Brown Clydebank shipbuilding facilities. There, shipyard workers paused long enough from their labors to accord "Wasp" a tumultuous reception as she passed. "Wasp"s impending mission was an important one – one upon which the fate of the island bastion of Malta hung. That key isle was then being pounded daily by German and Italian planes. The British, faced with the loss of air superiority over the island, requested the use of a carrier to transport planes that could wrest air superiority from the Axis aircraft. "Wasp" drew ferry duty once again to participate in Operation Calendar, one of many Malta Convoys.