Normandy Landings
In the new year, she was once again in Arctic convoy escort duty until March, when she was deployed in counter E-boat operations in preparation for the Normandy Landings, which would take place a few months later. She still escorted Arctic convoys, but she was being prepared for the invasion. And in April, when she was recalled for a boiler clean and minor re-fit, she was permanently assigned to Task Force 27 in the English Channel.
During a disastrous full scale rehearsal of the Utah Beach landing on 28 April, Opportune engaged German E-boats which had sighted and engaged eight American landing craft on their way to the Slapton Sands. The E-boats escaped after deploying a smokescreen, but over 638 US servicemen were killed in their attack. Many casualties were US Army personnel who were not properly trained and had difficulties with the life-jackets and other equipment, and drowned whilst awaiting rescue. The disaster nearly caused the D-day itself to be cancelled, as it was thought some ten soldiers with full knowledge of the operation could have been captured by the Germans, it was only the subsequent discovery of their bodies which saved the operation.
The actual landings on 5 June were much less eventful. Opportune patrolled in the eastern stretches of the English Channel, guarding against a German naval attack. She didn't encounter a single hostile boat, although she did engage E-boats in July and August, while supporting operations in France.
Read more about this topic: HMS Opportune (G80), Second World War