Understanding the North Swell in the BVI
Why It Happens, When It Shows Up, and Why Charter Itineraries Need to Change
If you’re chartering in the British Virgin Islands during the winter months, you’ll often hear captains mention “the north swell.” It’s one of the most important weather factors in the BVI—yet it’s also one of the least understood by visiting boaters.
A north swell can turn an otherwise perfect anchorage into an uncomfortable or unsafe place to spend the night. Knowing when it happens and which bays are affected can make a huge difference in your charter experience.
⸻
What Is a North Swell?
A north swell is long-period ocean energy created by large winter storms in the North Atlantic, often off the U.S. East Coast.
Even though these storms are far away, the swell they generate travels thousands of miles and reaches the Caribbean. Because this energy isn’t caused by local wind, conditions can look calm on deck while the boat still surges on its mooring.
Key characteristics of a north swell: • Long, rolling wave periods • Powerful surge inside exposed bays • Minimal local wind • Can wrap into anchorages that are usually calm
⸻
When Does North Swell Season Occur?
North swells most commonly affect the BVI between December and March, right in the middle of peak charter season.
They’re most likely after: • Strong winter cold fronts in the U.S. • North Atlantic storm systems intensifying • Periods of lighter trade winds
Some weeks you’ll never notice it. Other weeks, it can dominate itinerary decisions.
⸻
Why North Swells Are Hard on Mooring Balls
North swell doesn’t just affect comfort—it creates significant mechanical stress.
When swell enters a bay: • Boats surge forward and backward • Mooring pendants snap tight and slack repeatedly • Chains and hardware experience shock loading • Stress is transferred directly to the seabed anchor
Unlike steady wind load, long-period surge creates repeated impact forces, which can: • Accelerate hardware fatigue • Damage mooring components • Increase risk of failure
For this reason, boats should not remain on moorings in bays exposed to north swell, even if the weather otherwise looks good.
⸻
Popular Charter Anchorages Most Impacted by North Swell
These are high-traffic charter destinations that can become uncomfortable or unsafe during a north swell.
Commonly Affected Bays:
• Cane Garden Bay (Tortola) - A favorite overnight stop, but very exposed to northerly swell.
• White Bay (Jost Van Dyke) - Often calm in summer, but winter swell can cause heavy surge.
• West Coast of Virgin Gorda - Including The Baths, Devil’s Bay, and Spring Bay—spectacular during the day, but poor overnight choices when swell is running.
These bays may look inviting, but conditions can deteriorate quickly once swell energy wraps inside.
⸻
Better Alternatives During a North Swell
When north swell is present, the smart move is shifting to protected, south-facing or enclosed anchorages.
Safer, More Comfortable Options:
• Marina Cay – Excellent protection and a popular fallback
• Little Harbour (Jost Van Dyke) – One of the best north-swell refuges
• Great Harbour (Jost Van Dyke) – Well protected and lively ashore
• The Bight (Norman Island)
• Cooper Island (Manchioneel Bay)
These locations stay calm when exposed beaches are rolling.
⸻
Adjusting the Itinerary Is Part of Smart Seamanship
One of the biggest misconceptions charter guests have is that changing plans means something went wrong.
In reality: • Weather-based itinerary changes are normal • A short relocation can dramatically improve comfort and safety • Protecting moorings protects everyone who uses them
If your captain recommends moving because of north swell, it’s a sign of good judgment—not bad luck.
⸻
Final Takeaway
North swell is a natural and predictable part of winter sailing in the BVI. It doesn’t mean your charter is compromised—it just means your plans need to flex.
By avoiding exposed bays, choosing protected anchorages, and respecting the stress swell places on mooring systems, you help: • Keep guests safe • Protect boats • Preserve moorings for everyone
A calm night in a protected harbor will always beat a famous beach with surge.
BoatyBall publishes the morning lifegaurd report that will highlight if there is a North Swell. If you want to be updated make sure to allow for notifications from the BoatyBall Community “Trip Planning” page.
Fair winds and smooth nights. ⚓
