Submarine · 1903–1911 · West Sussex, United Kingdom

HMS/m A1

Also known as HMS A1, A1 submarine, Holland A1.

Lying in 9 to 12 metres of water off Bracklesham Bay, HMS A1 holds a unique place in British naval history: she was the very first submarine designed and built in this country for the Royal Navy. Constructed by Vickers in 1903, she had already survived one sinking — a collision with SS Berwick Castle in 1904 that killed eleven crew before she was raised — when she was repurposed as an unmanned torpedo target.

In August 1911, operating on automatic pilot, she sank for good off Selsey Bill. Tidal currents slowly dragged her five miles along the seabed to her present position. The hull is virtually intact, with the bow standing proud while the stern disappears beneath a sandbank.

StatusProtected sitePermitRequired
Type
SubmarineBritish
Year built
1903Vickers
Lost
August 1911Foundering
Casualties
0
Depth
9–12 m
Location
West Sussex, United KingdomEnglish Channel

4 of 6 facts above are cited in Sources below.

Deeper than 23 of the 185 wrecks on the map with a recorded depth.

History and LossLost August 1911 · Foundering · West Sussex, United Kingdom.

She had gone down once before: in March 1904 a collision with SS Berwick Castle sank her with the loss of 11 crew, and she was raised. The Royal Navy's first submarine to be both designed and built in Britain, she ended her days as an unmanned target for torpedo trials, and it was while running on automatic pilot off Selsey Bill that she sank.

Over time tidal currents carried the wreck approximately 5 miles to Bracklesham Bay.

Built 1903 by Vickers; 8 years in service, also recorded as HMS A1 and A1 submarine and Holland A1. Lost August 1911, foundering.

0lives lost on August 1911.

Condition of the WreckIntact, in 9–12 m, on soft sand.

Intactness

Virtually intact. Pressure hull apparently intact. Bow stands proud of seabed, stern buried under sandbank. Partially buried in soft seabed.

Notable Features

  • First British-designed submarine
  • Virtually intact pressure hull
  • Designated historic wreck since 1998

Regulations and RestrictionsProtected site · Permit required.

This is a legally protected site. Protected wreck under the Protection of Wrecks Act 1973 (Historic England (licences on behalf of the Secretary of State)). A permit is required to dive this site.

Designated historic wreck. No interference without licence from the Secretary of State.

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

Nationality
British
Flag
United Kingdom
Builder
Vickers
Propulsion
Petrol-electric
Loss date
August 1911
Latitude
50.74° N
Longitude
0.92° W
Water body
English Channel
Protection regime
Protection of Wrecks Act 1973 — designated historic wreck since 1998
Artefact restrictions
Designated historic wreck. No interference without licence from the Secretary of State.
War grave
No
Protected
Yes
Permit required
Yes
Condition
Intact
Seabed
Soft sand

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.

  • Contains public sector information licensed under the Open Government Licence v3.0. Historic England.

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/m A1?

HMS/m A1 is the wreck of a submarine, off West Sussex, United Kingdom, at 12 metres. HMS/m A1 foundered in 1911.

How deep is the HMS/m A1?

HMS/m A1 lies at 9 to 12 metres, Bracklesham Bay, near East Wittering, West Sussex (originally sank off Selsey Bill).

How did the HMS/m A1 sink?

HMS/m A1 foundered on August 1911, off West Sussex, United Kingdom. No lives were lost.

Is the HMS/m A1 protected?

Yes. HMS/m A1 is protected: protected wreck under the Protection of Wrecks Act 1973 (Historic England (licences on behalf of the Secretary of State)).