The Battle of Sept-Îles was a naval action fought on the night of 22/23 October 1943 during World War II as part of the Atlantic campaign. The battle took place off the Sept-Îles near the French coast in the English Channel between a light cruiser and six destroyers of the British Royal Navy hoping to intercept, a German blockade runner, which was accompanied by German torpedo-boat destroyers flotillas of the German Kriegsmarine. In fact, it is likely that the British vessels were caught in an ambush, and the action ended with the sinking of and the scuttling of after suffering damage; over 500 British sailors lost their lives. The battle was the last surface fleet action of the war where the Royal Navy was defeated, and the last German surface fleet action victory.
Background
By mid-1943, the Battle of The Atlantic had swung the Allies' way, and the Royal Navy went on the offensive. In August 1943, Plymouth Command was ordered to develop an operation to regularly harry German shipping, with a secondary aim of drawing German naval resources into a fight in order to destroy as many of the warships as possible before invading France.
C-in-C Plymouth Vice-Admiral Ralph Leatham came up with Operation Tunnel, in basic terms, an offensive sweep along the coast of western France - the first being on the night of 5/6 September. Three more followed, with no incident recorded. Then of the night of 3/4 October, Hunt-class escort destroyers HMS Limbourne, Tanatside and Wensleydale, plus fleet destroyers HMS Grenville and Ulster exchanged fire with German 'Elbing'-type torpedo-boat destroyers T-22, T-23, T-25, T-27, with Grenville and Ulster suffering light structural damage. Four more Tunnels were run between 13 and 18 October. The RN's tactics were always the same, and thus very predictable.
On 22 October, British authorities gained intelligence about the movement of the German blockade runner, Münsterland, which had departed Brest and was carrying an important cargo of latex and strategic metals. In all likelihood, the Münsterland intelligence was 'bait' to lure out the RN force and ambush them. At the briefing Lieutenant Commander Roger Hill commanding the Grenville voiced his reservations to senior staff about the predictability of the tactics and the lack of training between the vessels, going so far as to say "don't let's go", but his advice was not heeded.
was assigned to the operation for the first time, with its skipper Captain George Voelcker in charge, and on 22 October the British force put to sea from Plymouth. With Charybdis were the fleet destroyers and and four s: , , and .
Six German minesweepers of the 2nd Flotilla and two radar-equipped patrol boats escorted Münsterland in a well-rehearsed procedure. The blockade runner was then joined by five Type 39 torpedo boats of the 4th Torpedo Boat Flotilla, commanded by Franz Kohlauf.
Soon after midnight the British force conducted a radar sweep at while some west of Brittany. Meanwhile, at the same time German radar operators picked them up and carefully tracked them and then promptly relayed the information to the German ships. These warnings were intercepted by the Hunt destroyers and by Plymouth Command but Charybdis for some reason did not pick them up.
Contact
Münsterland was turned back out of harm's way, while the German torpedo-boats lay in wait for the British force. Charybdis picked them up on her own radar at a range of at 01:30 and signalled the destroyers to increase speed but only the rear destroyer, Wensleydale, picked up the signal. Her overtaking the rest of the force caused confusion, compounded when the first German torpedoes arrived and friendly star shells illuminated the leading British ships instead of the Germans. By now the British formation had lost cohesion.
The British force was visible against the lighter horizon and the Germans were further aided by a rain squall approaching from the south-west. Visibility was poor with low clouds and there was a long heavy swell. Kohlauf saw the silhouette of the larger British cruiser and believing he had been surprised gave the immediate order to turn and flee but not before ordering every ship to launch their torpedoes.