The British were just as successful (if not more so) at the beginning of the war in anti-shipping operations as the Germans were.
Really... From June 1940 to February 1941 the Luftwaffe Fw200 units alone sank 365,000 tons of Allied shipping. The Luftwaffe sank, crippled or damaged about 300 vessels of varying size in the 10 days in and around Operation Dynamo (Dunkirk).
Just read about the operations flown by 2 Group against German shipping and the success of British anti-shipping operations in the Med, like the Battle of Taranto or the Battle of Cape Matapan.
The Battle of Taranto was the British sneak attack against Italian naval units laying at anchor. It was a daring raid, but only one of the three Italian battleships damaged was put out of action for more than seven months.
Little more than a month later at noon on January 10th, 1941
HMS Illustrious, the carrier whose planes had attacked the Italian fleet at Taranto, along with the main forces of the Mediterranean Fleet, consisting of
HMS Warspite, HMS Valiant and 7 destroyers came under attack by 25 or more Ju87 and Ju88 bombers.
Illustrious was severely damaged as a result of 6 direct bomb hits and several near misses, which caused fires and disabled her steering gear.
Later the same day the Luftwaffe returned with about 30 aircraft and attacked the fleet again in which another hit was was made on Illustrious, and HMS Valiant was also damaged. The crippled HMS Illustrious was withdrawn from the Med and repaired in the United States. She did not return to action until 1942. The Luftwaffe lost 6 or 7 aircraft in the attack.
The Battle of Cape Matapan was a significant RN victory at sea sinking three Italian cruisers and two destroyers. However at the same time of the war during the German invasion of Greece the Luftwaffe all but destroyed the entire Hellenic Royal Navy sinking 25 ships including two battleships. The surviving cruiser
Averof and six destroyers managed to escape and joined the RN in the Med.
Also, at the time of the sinking of HMS Repulse and HMS Prince of Wales, Japan was probably the undisputed master of anti-shipping operations.
Well, that's the myth, but is it supported by the facts? By that time I would bet both the Luftwaffe and RAF Coastal Command were far more experienced in anti shipping operations.