text: A Mosquito from the RAF Film Unit accompanied the raiders and a fighter escort was provided by 11 Group and 12 Group, consisting of 11 Mustang Mk IIIs, 42 Spitfire Mk IXs and 26 Spitfire XVIs. The gun emplacements were at the north and south ends of the island and three aiming points were chosen, two for 9 Squadron and one for 617 Squadron. Thin stratocumulus cloud was encountered from  and six of the 9 Squadron bombers were to act as wind finders, the results being broadcast to the rest of the squadron at H minus 5. As 9 Squadron flew towards the island, they were surprised to see 617 Squadron attacking, climbed  to keep out of the way and circled while waiting for their fighter escort. The attack by 617 Squadron was made in two waves against hardly any anti-aircraft fire and all bar one aircraft bombed. Photographic evidence showed two hits on aiming point H and several near misses, which added to the damage. Another attack by the Main Force was planned but the war ended before it took place.
  Aftermath
  Analysis
  In 1991, Alan Cooper wrote that during March 1945, 156 day-sorties were flown, 31 with Grand Slams and 40 with Tallboys. An analysis of the bombing accuracy of 617 Squadron and 9 Squadron on Tallboy sorties found that, using different bomb sights and bombing from heights between , 1 per cent of the Tallboys dropped by 617 Squadron were gross errors [defined as missing the aiming point by more than ] against 10 per cent of the Tallboys dropped by 9 Squadron. Unlike the Tallboy, the Grand Slam was designed to penetrate concrete roofs and was more effective against fortifications than earlier bombs. By the end of the war, 41 Grand Slams had been dropped on operations although in 2004, Stephen Flower wrote of 42 bombs, a figure he repeated in his 2013 publication. in 1947 Sir Arthur Harris wrote,