Convoy ONS 5

Convoy ONS 5
Part of World War II
Date 29 April-6 May 1943 Location North Atlantic Result British Victory
Belligerents
Germany	United Kingdom  Canada
Commanders and leaders
Admiral Karl Dönitz	Convoy Comm: JK Brook RNR Escort B7: Cdr Peter Gretton
Strength
Star 16 U-Boats Finke 27 U-boats	42 ships 7 escorts
Casualties and losses
7 U-boats sunk 7 U-boats damaged	13 ships sunk (63,000 gross register tons (GRT))

ONS 5 was the 5th of the numbered ONS series of Slow trade convoys Outbound from the British Isles to North America. The North Atlantic battle surrounding it in May 1943 is regarded as the turning point of the Battle of the Atlantic in World War II. The battle ebbed and flowed over a period of a week, and involved more than 50 Allied ships and their escorts, and over 30 U-boats. It saw heavy losses on both sides. However it was almost the last Allied convoy to do so, while losses inflicted on attacking U-boats and U-boat groups became a besetting feature of the campaign; As such it is seen as the point when the tactical and strategic advantage passed to the Allies, and ushered in the period known to Nazi Germany's Kriegsmarine as Black May.