At 07.55 hours on 13 June 1944, U-107 missed the unescorted and unarmed Lark (Master James L. Abbott) with a torpedo and again at 08.15 hours about 32 miles southeast of Cape Sable. The U-boat then surfaced off the starboard quarter of the fishing vessel and fired at 08.30 hours a warning shot over the ship. The diesel engines were secured immediately and the crew of two officers and 25 crewmen abandoned ship in five dories, with the exception of the master and the cook who remained on board. The U-boat began shooting at the rigging, deck and hull with the 3.7cm and 2cm guns. Hits were made on the pilot house and in the hull above the waterline and the mainsail and riding sail were shot away. At daybreak, 40 minutes later, the U-boat departed.
The master and the cook started the engines at 15.30 hours and picked up all men within one hour. They arrived at Boston at 06.30 hours on 15 June.