On the night of 21/22 April 1944, the 4th Flotilla, now consisting of T24 and her sisters T27 and T29, transferred from Cherbourg to Saint-Malo.
After laying a minefield off the Sept-Îles on the north coast of Brittany on the night of 25/26 April, the flotilla was engaged by an Allied force that consisted of the light cruiser HMS Black Prince and the destroyers HMS Ashanti, HMCS Athabaskan, HMCS Haida and HMCS Huron off the Île de Batz.
The Allied ships were engaged by German coastal artillery without effect and Korvettenkapitän Franz Kohlauf, the flotilla's commander, headed west in search of the Allied ships, but the Germans were spotted first by Black Prince's radar at a range of 21,000 yards (19,000 m) at 02:07.
They detected the Allied ships shortly afterwards and reversed course.
The Allied ships were faster than the torpedo boats and had closed the range to 13,000 yards (12,000 m) by 02:20 when Black Prince began firing star shells.
The destroyers began firing at T24 and T27 at a range of 9,000 yards (8,200 m) as Black Prince hung back in support until one of her forward turrets jammed.
The Allied fire was accurate and one shell struck T27 at 02:31 and reduced her speed to 12 knots (22 km/h; 14 mph); Kohlauf ordered her into Morlaix Bay and the Allies lost her radar reflection amongst the rocks of the bay.
T24 had fruitlessly fired her aft torpedo tubes at her pursuers and was then hit by two shells in her superstructure that started fires that were quickly doused.
She fired her remaining torpedoes to no effect at 02:54 and, about that same time, a shell disabled T29's rudder.
Ashanti and Huron concentrated on T29 while Haida and Athabaskan continued their pursuit of T24.
They disengaged before T24 reached Saint-Malo, and returned to help sink T29.

After emergency repairs, T27 joined T24 in Saint-Malo during the night of 26/27 April.
The sisters departed Saint-Malo bound for Brest on the night of 28/29 April and were spotted by British coastal radar.
They were intercepted by Haida and Athabaskan off Île Vierge.
Haida opened the engagement by firing a star shell at 04:12; the Germans laid a smoke screen in response and turned away.
The sisters fired all of their torpedoes as they turned, T24 firing three off the wrong side of the boat, but one of the others hit Athabaskan.
Shortly afterwards, she blew up, probably from a magazine explosion, and sank at 04:42.
Haida pursued T27, badly damaging her.
While maneuvering, T27 accidentally ran aground and the Canadian destroyer continued to engage until she started a large fire and then returned to the site where Athabaskan had sunk to rescue survivors.
T24 and a pair of minesweepers failed in their attempt to pull T27 off and then T24 rescued 47 survivors from Athabaskan on the way to Brest.
She struck a mine en route, but was only damaged.
The 4th Torpedo Boat Flotilla was then disbanded and the boat was assigned to the 8th Destroyer Flotilla.
After repairs, T24 was ordered to Cherbourg on 19 May, but struck another mine and was under repair for the next several weeks.

On the night of 8/9 June, the four ships of the 8th Flotilla set out from Brest for Cherbourg, but were intercepted by eight Allied destroyers of the 10th Destroyer Flotilla in the Battle of Ushant.
The German ships had been spotted first and the British opened fire, with the Germans responding with a four-torpedo salvo from each destroyer that missed when the Allied ships turned to evade them; T24, the trailing ship in the formation, did not fire because she had no visible targets.
The British fire was extremely effective, with Z24, immediately ahead of the torpedo boat, badly damaged only moments after firing her first salvo.
The range was so close that both sides engaged with their 40 mm (1.6 in) or 3.7 cm anti-aircraft guns which appreciably added to the damaged suffered by Z24.
The Allied ships hit the German destroyer five times before she was able to lay smoke and disengage, followed by T24.
Haida and Huron pursued the pair until they passed over a British minefield and lost track of the German shi
On the night of 21/22 April 1944, the 4th Flotilla, now consisting of T24 and her sisters T27 and T29, transferred from Cherbourg to Saint-Malo. After laying a minefield off the Sept-Îles on the north coast of Brittany on the night of 25/26 April, the flotilla was engaged by an Allied force that consisted of the light cruiser HMS Black Prince and the destroyers HMS Ashanti, HMCS Athabaskan, HMCS Haida and HMCS Huron off the Île de Batz. The Allied ships were engaged by German coastal artillery without effect and Korvettenkapitän Franz Kohlauf, the flotilla's commander, headed west in search of the Allied ships, but the Germans were spotted first by Black Prince's radar at a range of 21,000 yards (19,000 m) at 02:07. They detected the Allied ships shortly afterwards and reversed course. The Allied ships were faster than the torpedo boats and had closed the range to 13,000 yards (12,000 m) by 02:20 when Black Prince began firing star shells. The destroyers began firing at T24 and T27 at a range of 9,000 yards (8,200 m) as Black Prince hung back in support until one of her forward turrets jammed. The Allied fire was accurate and one shell struck T27 at 02:31 and reduced her speed to 12 knots (22 km/h; 14 mph); Kohlauf ordered her into Morlaix Bay and the Allies lost her radar reflection amongst the rocks of the bay. T24 had fruitlessly fired her aft torpedo tubes at her pursuers and was then hit by two shells in her superstructure that started fires that were quickly doused. She fired her remaining torpedoes to no effect at 02:54 and, about that same time, a shell disabled T29's rudder. Ashanti and Huron concentrated on T29 while Haida and Athabaskan continued their pursuit of T24. They disengaged before T24 reached Saint-Malo, and returned to help sink T29.
After emergency repairs, T27 joined T24 in Saint-Malo during the night of 26/27 April. The sisters departed Saint-Malo bound for Brest on the night of 28/29 April and were spotted by British coastal radar. They were intercepted by Haida and Athabaskan off Île Vierge. Haida opened the engagement by firing a star shell at 04:12; the Germans laid a smoke screen in response and turned away. The sisters fired all of their torpedoes as they turned, T24 firing three off the wrong side of the boat, but one of the others hit Athabaskan. Shortly afterwards, she blew up, probably from a magazine explosion, and sank at 04:42. Haida pursued T27, badly damaging her. While maneuvering, T27 accidentally ran aground and the Canadian destroyer continued to engage until she started a large fire and then returned to the site where Athabaskan had sunk to rescue survivors. T24 and a pair of minesweepers failed in their attempt to pull T27 off and then T24 rescued 47 survivors from Athabaskan on the way to Brest. She struck a mine en route, but was only damaged. The 4th Torpedo Boat Flotilla was then disbanded and the boat was assigned to the 8th Destroyer Flotilla. After repairs, T24 was ordered to Cherbourg on 19 May, but struck another mine and was under repair for the next several weeks.
On the night of 8/9 June, the four ships of the 8th Flotilla set out from Brest for Cherbourg, but were intercepted by eight Allied destroyers of the 10th Destroyer Flotilla in the Battle of Ushant. The German ships had been spotted first and the British opened fire, with the Germans responding with a four-torpedo salvo from each destroyer that missed when the Allied ships turned to evade them; T24, the trailing ship in the formation, did not fire because she had no visible targets. The British fire was extremely effective, with Z24, immediately ahead of the torpedo boat, badly damaged only moments after firing her first salvo. The range was so close that both sides engaged with their 40 mm (1.6 in) or 3.7 cm anti-aircraft guns which appreciably added to the damaged suffered by Z24. The Allied ships hit the German destroyer five times before she was able to lay smoke and disengage, followed by T24. Haida and Huron pursued the pair until they passed over a British minefield and lost track of the German shi
German torpedo boat T24