Submarine · 1918–1932 · Dorset, United Kingdom

HMS M2

Also known as M2, HMS M2 submarine.

There is truly nothing else like HMS M2 anywhere in the world. Originally completed in 1919 as a submarine monitor carrying a massive 12-inch gun, she was converted in 1927 into the world's first undersea aircraft carrier, fitted with a watertight hangar and catapult for a tiny Parnall Peto floatplane.

On 26 January 1932, during a routine exercise off Portland, water flooded through the hangar and she went down with all 60 hands. The salvage investigation found those hangar doors standing open — a haunting detail that has fuelled debate ever since.

She rests upright and intact at around 33 metres in Lyme Bay, her 90-metre hull still unmistakably that of a submarine, the cylindrical hangar forward of the conning tower instantly recognisable.

StatusWar graveStatusProtected site
Type
SubmarineBritish
Year built
1918Vickers, Barrow-in-Furness
Lost
January 26th, 1932Flooding
Casualties
60
Length
90.14 m7.52 m beam
Depth
31–35 m
Location
Dorset, United KingdomLyme Bay

3 of 7 facts above are cited in Sources below.

Deeper than 114 of the 185 wrecks on the map with a recorded depth.

History and LossLost January 26th, 1932 · Flooding · Dorset, United Kingdom.

Flooded through the aircraft hangar during a training exercise in West Bay, Dorset. The hangar doors were found open during the subsequent salvage investigation. The world's first undersea aircraft carrier — originally armed with a 12-inch gun, later converted to carry a Parnall Peto seaplane launched by catapult and recovered by crane. Entire crew of 60 killed.

Built 1918 by Vickers, Barrow-in-Furness; 14 years in service, also recorded as M2 and HMS M2 submarine. Lost January 26th, 1932, flooding.

60lives lost on January 26th, 1932.

Condition of the WreckIntact, lying upright, bows pointing NNE, in 31–35 m.

Intactness

Still in one piece, sitting upright on the seabed. Hangar doors found open. 90 metres long.

Notable Features

  • World's first undersea aircraft carrier
  • Hangar for Parnall Peto seaplane
  • Catapult launch system
  • Designated war grave
  • Intact 90m submarine

Regulations and RestrictionsWar grave · Protected site.

This is a war grave, where human remains may be present and a legally protected site. Protected place under the Protection of Military Remains Act 1986 (Ministry of Defence).

No disturbance, removal or interference with remains or artefacts. Controlled site under Military Remains Act.

Additional Details15 further fields held for this wreck and not shown above.

Nationality
British
Flag
United Kingdom
Builder
Vickers, Barrow-in-Furness
Propulsion
Diesel-electric
Loss date
January 26th, 1932
Latitude
50.58° N
Longitude
2.57° W
Water body
Lyme Bay
Protection regime
Military Remains Act 1986 — designated war grave
Artefact restrictions
No disturbance, removal or interference with remains or artefacts. Controlled site under Military Remains Act.
War grave
Yes
Protected
Yes
Permit required
No
Condition
Intact
Orientation
Upright, bows pointing NNE

Sources and VerificationEvery cited fact on this page traces to a published source.

Background reading is listed for context and is not counted as a citation for the facts above.

A further 3 fields were derived from the wreck’s recorded position rather than taken from a source.

Licences and credits for the open data used on this site are on the Attribution page.

Frequently Asked Questions

What is the HMS M2?

HMS M2 is the wreck of a submarine, off Dorset, United Kingdom, at 35 metres. HMS M2 flooded and sank in 1932.

How deep is the HMS M2?

HMS M2 lies at 31 to 35 metres, Approximately 5 miles NW of Portland Bill, Lyme Bay, Dorset.

How did the HMS M2 sink?

HMS M2 flooded and sank on January 26th, 1932, off Dorset, United Kingdom. 60 people lost their lives.

Is the HMS M2 protected?

Yes. HMS M2 is protected: protected place under the Protection of Military Remains Act 1986 (Ministry of Defence). HMS M2 is recorded as a war grave.