Historical wreck fiche for the U171 off Groix.
Advanced deep submarine wreck off Groix.
Advanced deep submarine wreck off Groix.
Sous marin U171 is a deep World War II submarine wreck off Groix, resting across rocky plates and blocks with the conning tower standing out as the main landmark. The dive is advanced and atmospheric, with changing visibility and current, and it is better treated as a serious wreck profile than as a casual sightseeing dive.
Conservative baseline from public research. No community dives logged yet.
Depth range, seasonality, and planning context.
Reported Depth
38m - 40m
Depth Note
Reported around 38 to 40 m, with the conning tower rising about 7 m above the wreck.
Best Season
Late spring to early autumn
Typical Conditions
Atlantic wreck conditions are variable, with visibility and current changing from day to day.
Hazards, restrictions, and access requirements.
Key Hazards
Safety Notes
Stay outside the wreck, plan for variable current and visibility, and treat the site as a deep advanced dive with strict gas management.
Access Restrictions
Interior penetration is forbidden; wreck diving should stay outside the hull.
Legal Notes
Treat the wreck as a memorial and follow local penetration rules and operator briefings.
Community notes to help plan your visit.
Scuba Diving
A deep wreck dive around 38 m, with a notable conning tower rising about 7 m.
Freediving
Not a freedive site.
Snorkeling
Not a snorkel site.
Species commonly reported at this site, with direct links into their wildlife guides.
Community dive logs and visit reports for this site.
Average conditions based on logged dives & visits.
Planning answers for access, conditions, timing, and site logistics.
Last Updated
Research Sources
Historical wreck fiche for the U171 off Groix.
Dive-directory page with wreck dimensions and broader site context.
Historical U-boat registry with wreck position and depth context.
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