Mosquitoes are rare under sail in the BVI. At a sheltered mooring, fit the screens.

Yes, though on a sailing charter they're rarely a problem under way. In the British Virgin Islands, mosquitoes are most likely at night at sheltered moorings close to land, and sand flies bite on the beaches at dawn and dusk when the wind drops. Dengue is present, there is no malaria, and December to April is the drier, breezier season.

Where the bugs find you at anchor

Under sail, mosquitoes are rare. The exception is a sheltered mooring close to land, where on a still night they can come aboard. Enclosed spots such as the Bight at Norman Island and Deadman's Bay at Peter Island have that reputation, along with Trellis Bay, North Sound and the anchorage off Anegada. When you have a choice, a breezier mooring means fewer of them, and they tend to be worse after rain.

Dusk is the other window. A cockpit dinner at a still anchorage falls in the hours when no-see-ums and mosquitoes are out, and moorings tucked in near beaches or mangroves tend to have more midges. Put repellent on ankles, calves and any bare skin before sundowners, and fit the hatch screens before dark at a sheltered mooring. Picaridin is the easier choice on a boat, because DEET can damage many plastics and synthetic fabrics. Our picaridin vs. DEET comparison has the details.

Ashore, from beach bars to The Baths

On the beaches, sand flies come out at dawn and dusk when the wind drops and go for ankles and lower legs. Jost Van Dyke's beach bars at White Bay and Great Harbour run straight into those hours, while a daytime visit to The Baths on Virgin Gorda carries little exposure. Our Barbados sand fly guide explains the insect in detail.

Dengue is the disease to plan for, and its Aedes mosquito bites by day, with peaks after sunrise and in the late afternoon. Wear repellent ashore in Road Town and on beach days, and be stricter about it after rain. In August 2024 the Ministry of Health and Social Development reported rising dengue cases, including severe cases that needed hospital care, and national epidemiologist Harmonie Brewley-Massiah said the count was still below the epidemic threshold. The outbreak declared that month was next door in the US Virgin Islands, a separate territory. The ministry has warned that heavy rain and unmanaged breeding sites can drive dengue and chikungunya transmission.

The CDC's page also lists melioidosis, an infection caught through contact with contaminated fresh water, mud or soil, especially after heavy rain. Mosquitoes don't spread it. After a storm, keep cuts covered and stay out of muddy floodwater.

Where you're going

Here is how the main stops on a charter compare for a December–April trip.

One rule outlasts the trip. Any fever during or after your trip means a doctor visit, and you tell them you were in the British Virgin Islands. Flying on to Antigua or St. Maarten? Both have the same drier winter and the same beach sand flies; see our Antigua and St. Maarten briefings.

What travelers report

Paraphrased from a sailing forum thread and linked so you can read it in full. Wind, rain and where you pick up a mooring change the picture from one night to the next.

• BVI charter moorings (the Bight, Deadman's Bay, Trellis Bay, North Sound, Anegada) · night at anchor

  Sailors disagreed. A regular said mosquitoes are non-existent under sail and very rare on a mooring, while another had them on the boat and on the crew when moored just off shore. A third said most BVI mooring balls are close to land, so mosquitoes aboard at night are common. They named enclosed spots like the Bight and Deadman's Bay, and also Trellis Bay, North Sound and off Anegada. TripAdvisor ↗

Traveler questions