"Marchand" conducted exercises in Block Island Sound and Casco Bay, Maine, until departure from New York 22 February with convoy CU 15 for Ireland. About 2200 on 25 February, during a heavy gale, rammed . As "Marchand" came to the assistance of the badly damaged and burning merchant ships, "El Coston"'s bow rammed "Marchand" on her starboard side amidships damaging the plates of her forward control room. "Marchand" then stood by and received 28 survivors while took on board 33 others. The next day "Marchand" steamed for Bermuda as escort for El Coston. Shortly after midnight the 27th the remaining 56 crew members of "El Coston" had to abandon ship. After the merchant ship sank at 0142, "Marchand" directed her course for New York, where the survivors were debarked 1 March.