[2] On 19 February the US naval task unit TU 4.1.5 assumed escort responsibility with Gleaves-class destroyers USS Edison and Nicholson, Wickes-class destroyers USS Lea and Bernadou and the Canadian Flower-class corvette HMCS Algoma.

[4] Bernadou had been modified for long range escort work by replacing the fourth boiler and stack with an extra fuel tank.

[5] Nicholson had the only functional radar, though the merchant ship Toward could provide support with its High-frequency direction finding (HF/DF) set.

[6] Edison had no depth charge throwers, and was limited to a linear pattern rolled off the stern.

[11] U-155 approached the port quarter of the convoy in the pre-dawn hours of 22 February and torpedoed the British tanker Adellen and Norwegian freighter Sama.

[11] U-155 made another emergency dive while shadowing the convoy at 1042 hrs, but Edison did not detect the U-boat.

U-558 approached the convoy at 2120, but repeatedly turned away to avoid Bernadou's patrols until a squall provided cover at midnight.

"[7] U-158 found the convoy at 0425 hrs on 24 February and torpedoed the British tanker Empire Celt.

[18] U-558 found and sank the Eidanger, drifting and abandoned astern of the convoy, with gunfire and a torpedo.

[12] Lea investigated a DF bearing from Toward at 1515 and spotted U-558 20 miles astern of the convoy at 1707 hrs.

Edison finally spotted U-158 making another convoy approach at 2008 hrs and dropped 25 depth charges over the following six hours.