Resting upright at a depth of 96 metres, the experimental German vessel may be the only substantially complete survivor of its type.
A rare German military vessel from the Second World War has been identified on the floor of the Ionian Sea, more than eight decades after it disappeared while being towed for repairs.
The wreck is believed to be LS 6, a 12.5-metre Leichte Schnellboot—literally “light fast boat”—operated by Nazi Germany’s Kriegsmarine. It lies almost upright on a sandy seabed off Preveza in western Greece, at a depth of approximately 96 metres.
Although frequently described as a torpedo boat, LS 6 was more unusual than that name suggests. It belonged to a small experimental class of compact, aluminium-hulled vessels that combined aircraft-derived construction methods with high-performance marine engineering.
If the identification is correct, the wreck may be the only substantially complete surviving example of its type.
A search lasting 13 years
The search began in 2013, when German naval historian Peter Schenk passed information about a lost Kriegsmarine fast boat to researchers in Greece.
Historical researcher Giorgos Karelas and the AegeanTec diving team used German wartime records to narrow the search to an area between Lefkada and Preveza. A promising sonar target was eventually located at 96 metres.
Confirming its identity required a demanding technical dive. Divers Marinos Giourgas and Vasilis Spyropoulos descended using closed-circuit rebreathers and diver propulsion vehicles, equipment designed for deep dives where time, breathing gas and decompression must be carefully managed.
The vessel’s compact dimensions, aluminium construction and distinctive stern were consistent with the LS class. A camera lowered through an open engine-room hatch also recorded the outlines of two Junkers Jumo 205 diesel engines.
The strongest clue, however, was found at the bow: part of the boat’s towing line was still attached, while the remaining cable stretched across the seabed. This corresponds closely with the documented circumstances of the loss of LS 6.
An aircraft-inspired warship
LS 6 was built by Dornier at Friedrichshafen and commissioned in October 1941. Displacing approximately 12 tonnes, its light aluminium-alloy construction drew heavily on techniques used in aircraft manufacturing.
Its twin Junkers diesel engines reportedly gave it a maximum speed of around 37 knots—nearly 70 kilometres per hour.
The original concept was for a miniature attack craft that could be carried aboard a larger ship. Standard LS boats were designed with stern-firing torpedo tubes. Instead of turning towards its escape route after an attack, a boat could point its stern at the target, release its torpedoes backwards and accelerate away.
LS 5 and LS 6 were subsequently converted for anti-submarine operations. Their torpedo equipment was replaced by an internal depth-charge system, and the boats were fitted with a 20mm cannon.
This means that while LS 6 belonged to a light torpedo-boat class, it was probably operating as an anti-submarine, reconnaissance or transport craft when it was lost.
The final voyage of LS 6
LS 5 and LS 6 were sent to Greece in 1943. Because Allied forces controlled the Strait of Gibraltar, the small boats travelled overland by rail and road before entering service in the eastern Mediterranean.
On 24 September 1943, shortly after Italy signed an armistice with the Allies, LS 6 was attacked while accompanying German forces from Igoumenitsa towards Corfu.
Earlier accounts attributed the attack to British aircraft. Researchers involved in the identification now consider six Italian Reggiane Re.2002 fighter-bombers—operating for the Allies after the armistice—the more likely attackers.
Near-miss explosions reportedly damaged the thin aluminium hull and disabled the boat. German forces attempted to tow it to Piraeus for repairs, but the weakened vessel began taking on water and sank in the Ionian Sea.
No loss of life has been associated with the sinking.
Preserved in the darkness
After 83 years underwater, LS 6 remains surprisingly coherent. Its hull and superstructure are still recognisable, and the vessel stands almost upright on the seabed with its bow pointing northwest.
The depth that helped protect it also makes the wreck difficult and potentially dangerous to visit. At 96 metres, it lies far beyond the limits of ordinary recreational diving. Any future investigation would require specialist training, carefully planned breathing gases, redundant equipment and extensive decompression.
Its significance therefore lies less in its potential as a new dive attraction than in what it may reveal about an almost vanished branch of wartime naval engineering.
The vessel was not a famous battleship, nor was it involved in a decisive battle. It was a small experimental craft whose operational life appears to have been brief and unsuccessful. That is precisely what makes the wreck valuable.
Most surviving military vessels represent established and successful designs. LS 6 may instead preserve an engineering experiment—an attempt to combine the speed and lightness of an aircraft with the weaponry and endurance required of a naval craft.
For more than eight decades, that experiment remained hidden in the darkness of the Ionian Sea, its tow line still attached to the bow. Now the wreck may provide researchers with the only surviving physical evidence of how the unusual boats were actually constructed.
Sources
ProtoThema: Rare German Second World War wreck discovered in the Ionian Sea
Popular Mechanics: The 1943 wreckage of an experimental German ship
Identification and historical details are based primarily on the research and documentation released by the discovery team. A complete independent archaeological report has not yet been published.