'Pirat' was a U-boat wolfpack operation in the Atlantic against the ON.115 convoy (29 July/3 August 1942).
The wolfpack comprised U-43, U-71, U-164, U-210, U-217, U-454, U-511, U-552, U-553, U-588, U-597, U-607 and U-704, and for the loss of Korvettenkapitän Victor Vogel’s U-588 sank one 9,419-ton ship and damaged two ships (17,794 tons).
The outbound U-210 sighted and reported the ON.115 convoy of 41 ships supported by Lieutenant Commander C. Wallace’s Canadian Escort Group C3 (including the destroyers Saguenay and Skeena, and corvettes Agassiz, Gait, Louisburg, Sackville and Wetaskiwin). On 30/31 July the escorts repeatedly drove off the first U-boats to arrive, namely U-164, U-210, U-217, U-511 and U-553. U-588 was depth-charged and sunk by Skeena and Wetaskiwin.
On 1 August the 'Pirat' wolfpack established an initial patrol line of U-164, U-210, U-217, U-511 and U-553, and these boats were supplemented on the following day by the replenished U-43, U-71, U-454, U-552, U-597, U-607 and U-704. During the night Saguenay and Skeena had to depart for refuelling, and only Louisburg, Sackville and Agassiz remained with the convoy after Wetaskiwin failed to return after a hunt. In the afternoon the British destroyer Witch and Canadian destroyer Hamilton arrived from the Western Local Escort Force.
On 2 August U-552 sighted and reported the convoy before brining up U-71, U-217, U-553, U-597 and U-704. Kapitänleutnant Erich Topp’s U-552 torpedoed and damaged the 10,627-ton British tanker G. S. Walden and sank the 9,419-ton British Lochkatrine. Kapitänleutnant Ernst Mengersen’s U-607 sank the 7,176-ton Belgian Belgian Soldier, which had been damaged by U-553. No success attended the attacks by U-71, U-217 and U-552 on the convoy, and by U-597 on a straggler.
On 3 August the Germans terminated the operation because poor visibility made continued pursuit impossible.