Two propellers, not one.
The divers found two screw propellers, a strong clue that this was not the submarine recorded on their charts.
WHAT IT MEANT · A large twin-screw steamship deserved a new search through historic vessel records.
3D INVESTIGATION / 002 · ORIGINAL PHOTOGRAMMETRYLOTTE
LOTTE
HALM.
They went down expecting a submarine. What they found was a steamer that had spent eighty years hiding its identity beneath the North Sea.
HERO: ARTISTIC ATMOSPHERE · 3D MODEL: AUTHENTIC THIRD-PARTY RECORD BELOW
1941 · LOST IN THE GERMAN NORTH SEA2024 · WRECK SURVEYED & IDENTIFIED
ORIGINAL ROLEOil tanker · 1914
LOSTAugust 1941
LENGTHApproximately 71 m
DOCUMENTED BYDie Gezeitentaucher
00 / AN UNEXPECTED FINDNot a submarine.
Not a submarine.
A missing steamer.
On 5 October 2024, a three-diver team investigated an underwater target about 37 kilometres north of Norderney, off Germany. Official records had classified it as a submarine. The object was actually a large, almost completely overturned iron steamer with two propellers.
Researcher Holger Buss and his team used photogrammetry, measurements of surviving machinery and wartime records to identify it as Lotte Halm. Their 3D record lets us study the actual remains rather than a fictional rendering of the ship.
READ THE ORIGINAL FIELD STORY ↗01 / THE REAL 3D WRECKThe seabed,
The seabed,
captured.
Holger Buss created this photogrammetric scan from photographs captured by the dive team. The model below is embedded from its original Sketchfab listing; we haven't downloaded or recreated it.
Explore the ship as she rests today.
Rotate the inverted wreck, inspect its machinery and search for clues. On iPhone, use one finger to turn and two fingers to zoom.
© Holger Buss / Die Gezeitentaucher. Embedded with visible credit; original work remains theirs. Viewer requires internet. This is not a dive map.
OPEN ORIGINAL 3D MODEL ↗02 / UNDERWATER FORENSICSFive clues.
Five clues.
One identity.
Tap the numbered markers to discover how researchers used wreck features to identify the ship. The drawing is illustrative: only the model above records its measured appearance.
✧
ACCURATE RESEARCH, HONEST ILLUSTRATION
The five facts come from the team’s report. The simplified silhouette and pin positions above are a teaching aid, not a traced wreck plan, georeferenced image or navigational resource. Please use the actual 3D model to examine the wreck’s geometry.
03 / THE LIFE OF LOTTE HALMHow a steamer
How a steamer
disappeared.
Six stages from the ship's first purpose through wartime loss and modern identification. Accounts are drawn from the research team's published investigation.
19141914
An oil tanker is built.
The vessel began life in 1914, built as a tanker for German naval use during the First World War. She would later become a cargo steamer.
04 / HOW THEY KNEWIdentification
Identification
is evidence.
It wasn't a name painted on the hull. It was the agreement between different pieces of evidence that made the identification convincing.
Measurements showed a wreck around 71 metres long, narrowing the list of vessels lost in the area.
The team measured the triple-expansion engine cylinders and compared them with surviving Lloyd’s Register data.
Descriptions of the attack, fire and attempts to sink the vessel matched the archaeological evidence and helped resolve its identity.
05 / ORIGINAL RESEARCH & CREDITSSee the
See the
source material.
Holger Buss and his diving team deserve full credit for this investigation. Explore their original work directly.
FIELD INVESTIGATIONHolger Buss · Lotte Halm, Dive3D.eu↗ORIGINAL 3D MODELSteamer LOTTE HALM · holger.buss↗28-PAGE REPORT / GERMANHolger Buss · Prospektionsbericht: Wrack Z↗
Four people died in the attack. Their loss is part of the historical record, not a spectacle. This site is for heritage interpretation and historical learning, never dive navigation.
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