Martinique and St Lucia sit in the Windward Islands, exposed to the full Atlantic trade wind on their eastern (windward) coasts. Charter sailing is almost exclusively on the western (leeward) coasts where the islands provide shelter. The passages between the two islands (30M south) and the anchorage safety in trade wind swell are the main pilotage considerations. The weather is generally excellent from December to June; July to November is hurricane season and requires monitoring.
Windward and Leeward Coasts
The eastern (windward) coasts of Martinique and St Lucia face the full Atlantic and are exposed to the trade wind swell and the residual North Atlantic swell that runs year-round. They are not suitable for anchorage except in the most sheltered bays (Sainte-Anne on Martinique's extreme south-east is an exception). All charter sailing is on the western (leeward) coasts, which are protected by the island mass from the prevailing north-east swell. Even on the leeward side, afternoon trade winds of 20–25 knots are normal — anchorages open to any northerly can be rolly overnight.
Trade Wind Squalls
The most significant weather risk in the Windward Islands is the tropical squall — a fast-moving, self-contained convective storm that can bring 40+ knots and heavy rain for 15–30 minutes before passing. Squalls form rapidly over the mountains and can arrive with little warning on a vessel in the lee of the island. Signs: a dark, anvil-shaped cloud building over the ridge, a sudden increase in humidity and temperature, and a change in wind direction. When you see the cloud building to windward, reef down before the squall arrives — do not wait to see if it will miss. The squall will pass; a split sail or a capsize will not.
The Martinique–St Lucia Passage
The 30-mile passage between Le Marin (south Martinique) and Rodney Bay (north St Lucia) is the standard inter-island run. It takes 4–6 hours depending on conditions. The Saint Lucia Channel between the two islands is exposed to the Atlantic on its eastern end and carries the full north-east trade at 20–25 knots. The passage south (Martinique to St Lucia) is mostly on a beam reach — fast, lively, and manageable. The return north (St Lucia to Martinique) is close-hauled or motor-sailing into the trade wind — uncomfortable if the trades are blowing hard. Time the northward passage for early morning before the trade fills in.
Anchorages: Safety Notes
The main leeward anchorages (Rodney Bay, Marigot Bay, Soufrière Bay on St Lucia; Le Marin, Anse Mitan, Grande Anse d'Arlets on Martinique) are all suitable for overnight anchoring in normal trade wind conditions. Soufrière Bay is exposed to any northerly swell — in a northerly event, the bay becomes rolly and occasionally untenable. Grande Anse d'Arlets is open to the west and can be swell-affected in the afternoon. The safest overnight anchorage in St Lucia is Rodney Bay or the inner bay at Marigot — both are well sheltered.
Frequently Asked Questions
Q: Do I need to check out of Martinique before sailing to St Lucia?
A: Yes. Martinique is French territory (and thus EU); St Lucia is an independent Commonwealth nation. You must check out of Martinique at the capitainerie du port (marina office) at Le Marin before departure and check in to St Lucia at the customs and immigration office at Rodney Bay Marina on arrival. Carry passports for all crew. The process takes 1–2 hours at each end.
Q: What should I do if caught in a squall at anchor?
A: If anchored in a secure anchorage with good holding (sand or mud, not weed), stay put — the squall will pass in 20–30 minutes. Let out extra chain (minimum 5:1 depth ratio in the squall). If you are not confident in your holding or are near other boats, start the engine and be ready to motor forward onto the chain if the anchor drags. Brief your crew on the procedure before the squall arrives.