USCGC Sebago was a Lake-class cutter belonging to the United States Coast Guard launched on 12 April 1930 and commissioned on 2 October 1930.

[1] After 11 years of service with the Coast Guard, she was transferred to the Royal Navy as part of the Lend-Lease to the Allies and became HMS Walney.

After some time on convoy escort duty, Walney was selected for Operation Reservist as part of the Allied invasion of French North Africa.

Walney, together with Hartland were to break into Oran harbour and land troops that would take control of key facilities before they could be destroyed.

[3] Walney joined the Londonderry Sloop Division in June, and was assigned to escort the passage of the Atlantic convoys.

She returned to the Western Approaches on 9 September and was transferred to the 41st Escort Group to help defend convoys between the United Kingdom and West Africa.

She arrived two days later on 22 December and underwent another refit, this time involving the fitting of Huff-Duff equipment.

After her arrival in Londonderry, she was nominated for special duties during the planned North African landings (Operation Torch).

On arrival in November, the two sloops embarked troops to carry out a landing inside the harbour (Operation Reservist).

On board Walney at the time were 200 men of the American 2nd Battalion 6th Armored Infantry Regiment and a 35-strong US Naval contingent, with six US Marines.