France – Atlantic & Channel

France's Atlantic and English Channel coast is cold-water diving shaped by the tide. Around Saint-Malo the tidal range is among the largest in Europe, so dives are planned around slack water; further west, the Iroise Sea off Brest, Molène and Ouessant has kelp forests, strong currents, a small grey-seal colony and dozens of modern wrecks inside France's first marine natural park. South Brittany (Glénan, Groix, Quiberon, Belle-Île) is gentler, with granite reefs and many World War wrecks in 18–40 m, while the Vendée islands and the Basque coast near Hendaye add offshore wrecks and rocky walls exposed to Atlantic swell. Off Normandy and Cherbourg lie Second World War wrecks, several of them protected memorials. Expect 13–18 °C water, variable visibility and a drysuit or a thick wetsuit.

Facts

• Tides & slack water: Tides govern almost every dive: Saint-Malo's dive centre advertises the strongest tides in Europe and lists sites whose depth changes by up to 20 m with the tide; some Rance sites are dived only at slack water and with the agreement of the tidal power station. Higher tide coefficients (scale about 20–120, 'grandes marées' from 100) mean stronger currents, so centres plan departures around slack (étale). (Source: Saint Malo Plongée Émeraude; Wannadive; Routard) Check current tide tables (SHOM) with your centre.
• Atlantic swell & weather: Weather on the Atlantic side can change fast, so centres usually choose the site the evening before or at the last minute according to swell, wind, tide and divers' level. On Ouessant, entries and pick-ups in swell can be 'sporty' and fog is common. (Source: Centre Haliotis Plongée; Subagrec; Ouessant Subaqua)
• Water temperature & exposure: Monthly sea-surface averages at Brest are roughly 14.6 °C in June, 16.7 °C in July and 17 °C in August, and around 15–16 °C in October in Finistère (Source: cabaigne.net); early-June water off Normandy is around 13 °C (Source: vvanat.fr). Many divers use a drysuit – Saint-Malo's centre runs dedicated drysuit training – or at least a thick wetsuit with hood and gloves.
• Seasons: Island and coastal centres mostly run from April to October (Groix, Quiberon), May to November on Ouessant; Saint-Malo's club-centre dives year-round and Hendaye clubs dive into autumn. July–August is busiest, with morning-only departures at some islands. (Source: Subagrec; Centre Haliotis Plongée; Ouessant Subaqua; Angelus Plongée; Saint Malo Plongée Émeraude)
• Certification & depth limits: French law (Code du sport art. A322-77, annexes III-14a/b) defines aptitudes by depth: PE-20/PE-40/PE-60 for guided divers and PA-12/20/40/60 for autonomous divers. FFESSM/CMAS equivalents: Level 1 (1 star) = PE-20, Level 2 = PE-40 + PA-20, Level 3 = PE-60 + PA-60; the 40–60 m zone is reserved for holders of FFESSM, FSGT, UCPA, ANMP, SNMP or CMAS certificates. Foreign cards (PADI, SSI…) have no official equivalence; the dive director (directeur de plongée) sets your limits from your card and logbook and may ask for a check dive. (Source: Code du sport annexes, Préfecture des Côtes-d'Armor; FFESSM CODEP note) Check current rules.
• Medical certificate & licence: The FFESSM requires a yearly 'certificat d'absence de contre-indication' (CACI) from a doctor for scuba; clubs affiliated to it (e.g. Subagrec on Groix, Urpean in Hendaye) will not dive you without a valid medical certificate and an FFESSM licence or day pass, and Belle-Île's Angelus asks for proof of level, a medical certificate and a logbook. Bring a recent medical certificate even if your agency only uses a self-declaration. (Source: FFESSM medical forms; Subagrec; Urpean; Angelus Plongée) Check current rules with the centre.
• Wrecks, DRASSM & war graves: Wrecks and artefacts are maritime cultural property: anything found must be left in place and declared within 48 hours (Code du patrimoine L532-3); the DRASSM (Département des recherches archéologiques subaquatiques et sous-marines) handles declarations with the DDTM. Taking anything is forbidden. Some wrecks are memorials with extra rules – the troopship Léopoldville off Cherbourg needs prior authorisation from the maritime prefect, and entering U-171 off Groix has been banned since 1999. Many Second World War wrecks still hold munitions. (Source: Ministère de la Culture; vvanat.fr; Wannadive) Check current rules.
• Parc naturel marin d'Iroise: Created in 2007 around Ouessant, Molène and the Iroise Sea, the park protects the Molène archipelago's grey-seal colony – the southernmost in the Atlantic, at most about a hundred animals a year – by keeping their haul-outs undisturbed. Keep your distance from seals and resting sites and follow your centre's briefing. (Source: Espace des sciences / Sciences Ouest) Check current rules.
• Sept-Îles nature reserve: The Sept-Îles national nature reserve off Perros-Guirec, extended in 2023 to 19,700 ha with the Triagoz plateau and Île Tomé, shelters seabird colonies, grey seals and 2,500 ha of kelp forest. All species are protected and disturbing them is forbidden; all activity is banned inside the reinforced protection zone around Île Rouzic from 1 April to 31 August, and landing is allowed only on Île aux Moines. (Source: Réserve naturelle des Sept-Îles regulation leaflet, Perros-Guirec) Check current rules.
• Glénan archipelago: The Glénan combine Natura 2000, a national nature reserve, a classified site and other protections; underwater there are kelp forests, eelgrass meadows and maerl, and basking sharks may pass in spring. Use the municipal eco-moorings or anchor on sand away from eelgrass; drones are not allowed. (Source: 'Les Glénan – carnet du visiteur respectueux', Bénodet/Fouesnant 2026)
• Getting there: Ouessant is reached year-round by Penn ar Bed ferries from Brest (about 2 h 15) and Le Conquet (about 1 h); Belle-Île is about 45 minutes by boat from Quiberon; Groix is served by Compagnie Océane from Lorient; the Glénan are reached by boat from Concarneau or Bénodet. Hendaye has a TGV/regional station and Biarritz airport nearby. (Source: Ouessant Subaqua; Angelus Plongée; Subagrec; PlanetOcean)

Season

• Best months: Jun, Jul, Aug, Sep
• Acceptable: Apr, May, Oct
• Poor: Nov, Dec, Jan, Feb, Mar
• Water temperature: 9–18 °C

Brittany and the Channel: cold water (9–18 C), big tides; Glénan clubs run May to November and boats April to September. Late summer is best as spring plankton blooms cut visibility; dive at slack water. Few dive-specific sources.

Dive sites (46)

Brest & Iroise

• Amoco Cadiz – 15–30 m, intermediate
• Elektra – 18–20 m, beginner
• Kléber – 40–48 m, advanced
• Louis David – 20–25 m, intermediate
• Marco Polo – 23–26 m, intermediate
• Peter Sif – 40–56 m, advanced
• Swansea Vale – 28–31 m, intermediate
• Tombant du Belge – 25–50 m, advanced

Arcachon & Basque coast

• Arcachon blockhaus – 15–20 m, beginner
• Canyon (Hendaye) – 18–35 m, intermediate
• Chicharvel – 13–30 m, beginner
• Illarguita – 27–40 m, advanced
• Le Morutier (Cruz Segundo) – 50–57 m, advanced
• Les Esclaves – 25–40 m, intermediate
• Sunniva – 40–41 m, advanced

Crozon & Douarnenez

• Basse du Lys – 15–40 m, intermediate
• La Meuse – 28–30 m, intermediate
• Morgat – beginner
• Pointe de Pen-Hir & Tas de Pois – intermediate

South Brittany (Glénan, Groix, Quiberon, Belle-Île)

• Battleship France – 17–25 m, intermediate
• Elisabethville – 75–80 m, advanced
• L'Angers – 18–21 m, beginner
• L'Hanan – 22–24 m, intermediate
• La Truie – 5–14 m, beginner
• Pointe de Pen Men – 17–22 m, beginner
• Sperrbrecher 134 – 20–25 m, intermediate
• Thüringen – 7–13 m, beginner
• U-171 – 39–40 m, advanced

Saint-Malo & Côte d'Émeraude

• Bizeux – 3–20 m, beginner
• Fetlar – 17–28 m, beginner
• Fort de la Conchée – 10–20 m, beginner
• Frémur – 20–30 m, intermediate
• Hilda – 10–25 m, beginner
• La Catis – 15–40 m, intermediate
• Laplace – 15–25 m, beginner

Loire-Atlantique & Vendée

• John G. McCullough – 46–50 m, advanced
• Laos – 12–15 m, beginner
• Ours des Vieilles – 13–17 m, beginner
• Sequana – 43–45 m, advanced
• Yusenquashia Maru (Le Japonais) – 6–15 m, beginner

Côte de Granit Rose

• Le Squéouel – 5–20 m, advanced
• Pors Kamor (La Cale de Ploumanac'h) – 5–20 m, intermediate
• T-29 torpedo boat – 50–52 m, advanced
• Triagoz lighthouse – 10–40 m, intermediate

Normandy & Cotentin

• Léopoldville – 38–64 m, advanced
• USS Susan B. Anthony – 11–30 m, intermediate

Operators (9)

• Saint Malo Plongée Émeraude (SMPE) – dive centre, Saint-Malo
• Nautilus Dive Center – dive centre, La Richardais (Dinard)
• Ouessant Subaqua – dive centre, Lampaul, Ouessant
• CIP Glénan (Centre International de Plongée) – resort, Île Saint-Nicolas, Glénan
• Subagrec – dive centre, Port-Lay, Groix
• Angelus Plongée – dive centre, Le Palais, Belle-Île-en-Mer
• Centre Haliotis Plongée – dive centre, Portivy, Saint-Pierre-Quiberon
• PlanetOcean – dive centre, Hendaye
• Urpean – dive centre, Hendaye

Routes (4)

• Bay of Saint-Malo reefs and wrecks (SMPE)
• Belle-Île explorations (Angelus)
• Quiberon peninsula dives (Haliotis)
• Basque coast from Hendaye (Urpean)

Site positions are approximate unless marked otherwise and are for orientation only — never for navigation. Tides, currents and swell decide whether a site can be dived; plan with a local centre and current tide tables. Wreck and reserve rules change; many wrecks are protected cultural property or memorials, and some deep wrecks are technical dives.