NBM Dive Site Resource
SM UB-31 — Dover protected wreck (attributed)
Dover and the Strait of Dover, United Kingdom coastal waters, United Kingdom
Archaeological research attributes a Dover UB II wreck to UB-31, while correcting an older attack claim that actually concerned UB-78.
Save this dive site to your free member profile.
Featured Hero Photograph
Aquatic life at this dive site
What divers may encounter
Three reviewed connections are featured here. Sightings vary by season, conditions, and chance, so they are never guaranteed.
Aquatic life research in progress
NBM is reviewing a likely local species for this position.
Aquatic life research in progress
NBM is reviewing a likely local species for this position.
Aquatic life research in progress
NBM is reviewing a likely local species for this position.
Site media
Photographs
Three views rotate from the published gallery on each visit.
Contributor media
Dive videos
Three featured video positions are reserved on every profile.Regional location and nearby land
Location map
Regional view includes nearby land for orientation. Historical loss reports are not navigation fixes; no precise wreck position is inferred.Map data © OpenStreetMap contributors
Recent field observations
Diver-reported temperatures
Automatically checked observations from dives during the past 14 days. Three reports are visible at a time; scroll for more.A report that passes the automatic checks will appear here with the dive date, diver’s display name, and temperatures at each depth.
Reports are automatically checked for plausible dates, depths, and temperatures. They are observations, not forecasts; confirm conditions before diving.
Why divers know this place
Highlights
Archaeological research attributes a Dover UB II wreck to UB-31, while correcting an older attack claim that actually concerned UB-78.
Shipwreck-only module
The wreck
This section appears only on shipwreck records and brings the vessel, its loss, present condition, access, and responsible wreck-diving considerations into one place.
- Vessel type
- German World War I Type UB II submarine
- Year built
- 1915 (launched)
- Year sunk
- 1918
- Cause of loss
- Lost to a mine in the Dover barrage between late April and early May 1918.
- Present condition
- Diver-investigated UB II wreck attributed to UB-31 in the archaeological study.
- Penetration guidance
- External historical context only; no authorization for penetration, recovery or disturbance.
Before you arrive
Access notes
The thesis treats the individual identity as an attribution and records 27 m. The 2026 UK designation lists UB-31 as a protected place; no entry, damage or disturbance is authorized. Protected place under the 2026 UK designation order; confirm current rules and do not enter, damage or disturb the wreck. This record documents a wreck and its research history. It does not establish public charter availability or permission to visit. Confirm access with the responsible authorities and qualified local support; respect the site’s naval-heritage context.
Plan within your training
Conditions and hazards
Offshore weather and currents, depth and decompression exposure where applicable, low or changing visibility, entanglement, unstable or damaged metal and possible ordnance. Do not disturb remains or remove objects.
Independent resource notice
This record is a starting point for independent verification. Access, closures, moorings, weather, currents, depth, visibility, operator availability, and site conditions can change without notice. Confirm current information with the responsible operator, property owner, managing authority, or another qualified local source before planning or attempting a dive.