The northeast trade winds are the most reliable wind system on earth. They blow across the tropical Atlantic from roughly November through May with a consistency that European and American sailors, accustomed to the fickleness of temperate weather, find almost disorienting. In the charter belt of the eastern Caribbean — from the BVI at 18°N to Grenada at 12°N — the trades arrive from the east-northeast at 15-25 knots, day after day, week after week. Columbus used them to reach the New World. The sugar fleets used them to carry their cargo. The modern charterer uses them to sail between islands that are among the most beautiful in the world. The wind is a given. What matters is how you plan around it.
The trades: why they blow and what to expect
The trade winds are a planetary-scale phenomenon driven by the Hadley Cell — the large-scale atmospheric circulation pattern in which warm air rises at the equator, flows poleward at altitude, descends at the subtropical high-pressure zones (around 30°N and 30°S), and flows back toward the equator at the surface. The Coriolis effect — the earth's rotation deflecting moving air — turns this returning surface flow to the right in the northern hemisphere, producing the northeast trades.
In the Caribbean, this translates to:
December to February: The trades are at their steadiest. Wind speed averages 18-22 knots, direction east-northeast. Occasional reinforcements from cold fronts passing across the US mainland can temporarily increase wind speed to 25-30 knots ("Christmas winds") and shift the direction more northerly.
March to May: The trades lighten slightly, averaging 15-20 knots. The direction becomes more easterly. Sea state moderates. This is many experienced charterers' preferred window: reliable but less boisterous than midwinter.
June to November: Hurricane season. The trades weaken and become intermittent, replaced by lighter and more variable winds. From August through October, the risk of tropical storms and hurricanes is material, and most charter companies either close or operate with restrictions.
Windward and leeward: the fundamental geography
Every island in the eastern Caribbean has two faces. The windward side (east) receives the full force of the Atlantic trades and the ocean swell. It is rough, exposed, often cliffy, and almost always unsuitable for anchoring. The leeward side (west) is sheltered from both wind and swell, with calmer water, sandy beaches, and the anchorages that charter sailors use.
This windward/leeward division shapes every passage plan:
Sailing south (downwind): When moving south along the island chain, the standard approach is to sail down the leeward side of each island, cross the channel between islands (where you are exposed to the full trades and the Atlantic swell), and then tuck into the lee of the next island. The channel crossings are the demanding part — open water, 15-25 knots on the beam or slightly forward, with a 1-2m Atlantic swell. The coastal legs are sheltered and easy.
Sailing north (upwind): The return passage — beating into the trades — is harder work. The channels become windward beats in steep seas, and progress is slow. Many charter companies offer one-way charters (south only) to avoid this. When the return must be sailed, the strategy is to motor-sail through the channels, using the engine to maintain speed to windward while the sails reduce the rolling.
Channel crossings: the key passages
The distances between islands vary, and the character of each channel crossing differs:
BVI internal waters: 5-15 NM, sheltered by the island chain. The easiest sailing in the Caribbean.
Anegada Passage (BVI to St Martin): 90 NM of open ocean. A serious passage in trade-wind conditions — boisterous, exposed, and typically an overnight sail. Not a casual charter passage.
St Martin to St Barths: 15 NM, moderately exposed. A straightforward trade-wind reach.
Antigua to Guadeloupe: 40 NM, open and exposed. A full-day passage with beam-to-bow winds and Atlantic swell.
Dominica to Martinique: 25 NM. The wind shadow of Dominica's mountainous interior (the highest island in the eastern Caribbean at 1,447m) creates a notable dead zone off the leeward coast, followed by an abrupt return to full trades in the channel.
St Lucia to St Vincent: 35 NM. The Pitons of St Lucia are visible from St Vincent; the passage is a broad reach in consistent trades.
St Vincent to Bequia: 9 NM. Short, easy, and the gateway to the Grenadines.
Tobago Cays to Grenada (via Carriacou): 40 NM in stages. The passage from Carriacou to Grenada (25 NM) is the most exposed of the Grenadines chain.
Passage planning: practical principles
Depart early. The trades typically moderate overnight and build through the morning. Leaving at 06:00-07:00 for a channel crossing means starting in 12-18 knots rather than the 20-25 knots of midday.
Time the swell. Atlantic swell in the channels runs 1-2m from the northeast. It is most uncomfortable when the wind is against the current (particularly on spring tides). Check the tidal stream for each passage, though in the Caribbean, tidal effects are much smaller than in European waters.
Plan for the wind shadow. Each island creates a wind shadow on its leeward side that can extend 5-10 NM downwind. Approaching an island from the south, you may lose the wind entirely and need to motor the final miles to the anchorage. Leaving an island to the south, the wind will return abruptly as you exit the shadow — be ready with reduced sail.
Carry adequate sail. In 20+ knot trades, a reefed main and partially furled genoa is the standard working rig. Over-canvassing in trade-wind conditions is the most common cause of gear failure on Caribbean charters.
Weather resources for Caribbean passage planning
Wind forecasts: Windguru, PredictWind, and Windy provide reliable 5-7 day forecasts for Caribbean waters. Cross-reference at least two sources before committing to a passage.
GRIB files: Downloadable weather data files (Global Forecast System or European Centre models) can be viewed on tablet or laptop navigation apps. These provide wind speed and direction at 6-hour intervals and are the most useful single tool for passage planning.
VHF weather broadcasts: Most Caribbean nations broadcast weather forecasts on VHF; frequencies vary by country and are listed in the cruising guides.
Local knowledge: Ask other sailors. The cruising community in the Caribbean is generous with information, and the sailor who arrived yesterday from the island you are heading to can tell you more about current conditions than any forecast model.
The honest summary
Caribbean trade-wind sailing is not technically difficult, but it is physically demanding. The wind is persistent, the sea state in the channels can be rough, and the passages require planning and respect. A charterer who has sailed in the Mediterranean's lighter summer winds may be surprised by the Caribbean's energy.
The reward is consistency. In the Caribbean, you know what the wind will do. You can plan a passage with confidence that the forecast will verify. The sailing is fast, the conditions are warm, and the destinations — once you have crossed the channel and tucked into the lee — are among the most beautiful on earth.
