Île d'Oléron — Anse de la Maumusson
Maumusson Passage · S Oléron anchorage
45°50.6'N 001°13.0'W
Depth (HW)
2–5m
Bottom
sand
Alarm Radius
80m
Holding
Good Holding
Recommended Anchor Alarm Radius
80m
80m on sand — staging anchorage only for Maumusson transit. CRITICAL WARNING: the Maumusson passage is dangerous. Do NOT transit in W swell, strong winds, or near-ebb conditions. Slack water only, good visibility, calm sea state. When in doubt — do not pass.
About This Anchorage
The Anse de la Maumusson staging anchorage lies just N of the Maumusson passage at the S tip of Île d'Oléron — the narrow, shallow tidal strait connecting the Pertuis d'Antioche to the Gironde approaches. This is one of the most dangerous passages on the French Atlantic coast: tidal currents reach 4 kt, and in W swell with the ebb running, breaking seas fill the passage. Many yachts have been lost or severely damaged attempting this passage in unsuitable conditions. Use this anchorage only to stage a slack-water transit in ideal (calm, no W swell, neap tide) conditions. In any doubt, sail the Grande Passe de l'Ouest, 25nm to the W.
Protected From
N · NE · NW
Exposed To
S · SW · W
Setting Your Anchor
7:1 Scope — Atlantic Tidal Standard
With a 4–5m spring tidal range, the depth at your anchor point can change by up to 5m overnight. Use 7:1 scope minimum — in 4m at HW, lay 28m of chain as a minimum (excluding depth + freeboard). At LW (potentially 1–2m), the scope ratio increases automatically, providing extra catenary. Always verify the anchor is set firmly before reducing engine revs.
Tidal Depth Calculation
Before anchoring, calculate the depth at maximum LW (spring LW) using the SHOM tide tables for the nearest standard port. Subtract the spring tidal range (4–5m) from your HW depth to get the LW depth. For a 1.5m draft vessel, you need at least 1.8m at LW springs (with 0.3m safety margin) — if the anchorage will be shallower, either move to deeper water or ensure you are comfortable taking the ground on sand.
Oyster Stake Avoidance
Always check your proposed anchor position against the SHOM chart for oyster farm boundaries. At HW, oyster stakes may be submerged or barely visible — a dragging anchor on a falling tide can set you into a farm before the alarm sounds. Keep a minimum 200m clearance from all oyster farm boundary buoys.
Anchoring Rules
- Anchoring fee
- Free
- Maximum stay
- 2 days
- Permit required
- No
- Anchoring allowed
- Yes
Restrictions: MAUMUSSON PASSAGE: Attempt ONLY at slack water, neap tides, calm sea state, no W swell, good visibility. If ANY of these conditions are not met — do NOT transit. Use Grande Passe de l'Ouest instead. Many serious yacht accidents in this passage.
Hazards
- !MAUMUSSON PASSAGE: 4-kt tidal race; breaking seas in W swell + ebb — many yacht accidents; DANGEROUS
- !Exposed to SW/W ocean swell — this staging anchorage is untenable in any W/SW conditions
- !Tidal range 4–5m: passage shoals at LW — transit timing is critical to both direction and depth
- !Mobile sandbanks in approach: SHOM chart 7395 required — depths change season to season
Skipper's Tips
- →Consult the Reeds Almanac or RCC Pilotage Foundation North Biscay Pilot for the current year's Maumusson pilotage notes — the bar shifts every season.
- →If you hear on VHF that conditions are 'agité' at Maumusson — turn around. No schedule is worth this passage in a strong ebb.
- →In a good summer (light W swell, neap tides, mid-June to mid-September), this passage is do-able — but only at HW slack in a shallow-draft boat with an experienced crew.
Facilities
Nearest provisions: Le Château-d'Oléron (10nm)
Best Months & Season
June, July, August, September
Only attempt in summer (Jun–Sep) at neap tides, HW slack, calm sea state. Outside these conditions: sail the Grande Passe de l'Ouest. No tourist cruising value here — purely a transit staging point.
Recommended Anchor Types
Nearby Anchorages
Sleep peacefully at Île d'Oléron — Anse de la Maumusson
With a 4–5m tidal range overnight, your boat's position relative to nearby hazards changes as the depth drops. In July–August, neighbouring boats anchor close and the anchorage shifts with the tide. Safety Anchor Alarm continuously monitors your GPS position and sounds an instant alert if you drift outside your set 80m radius — so you can rest without worry.
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