What to do in a thunderstorm or high winds on a boat?

In short: a thunderstorm or a gale can almost always be anticipated thanks to the marine weather forecast. If the weather turns, the rule is simple: stay in port or reach shelter before the bad weather arrives. At sea, shorten sail, secure the crew and the boat, and keep the VHF radio on channel 16. If you're sailing with a captain or a crew, they make the calls: all you need to do is follow their instructions.

Plan ahead before every departure

• Check the marine forecast every morning, not just the land forecast: wind speed and direction, gusts, sea state, and risk of thunderstorms.
• Compare several sources: official forecasts (NOAA's National Weather Service and NOAA Weather Radio in US waters, Météo-France in French waters, the national weather service elsewhere), forecasts broadcast over VHF, and wind forecasting apps.
• Watch for Small Craft Advisories and Gale Warnings: in US waters, the National Weather Service issues a Small Craft Advisory from about 20 knots (the threshold varies by region) and a Gale Warning from 34 knots (force 8). Both are broadcast over VHF.
• Adjust your plans: a shorter leg, a better-protected anchorage, or a day in port beats an uncomfortable sail.
• Scout out shelter along your route: harbors and anchorages protected from the forecast wind direction. Avoid exposed anchorages with no natural protection whenever the wind is expected to build or shift. On a sailboat charter in Croatia, for example, the many islands offer shelter from every wind direction, as long as you've located them before the bora kicks in.
• Pay close attention to the base briefing: the local team knows the prevailing winds and the hazards of the area.

At what wind speed should you stay in port?

Wind is measured on the Beaufort scale. In marine forecasts, a gale starts at force 8. On a sailing vacation, conditions become uncomfortable well before that.

Most bareboat charter contracts prohibit leaving port above a certain wind speed. This limit is spelled out in your contract, and the base may remind you of it during the briefing.

What should you do in a gale at sea?

Keep the crew safe

• Have everyone wear a life jacket, and anyone who needs to go on deck wear a harness clipped to a jackline (a webbing strap running from bow to stern along the deck).
• Gather passengers in the cockpit or below deck, with kids below deck.
• Keep movement on deck to the bare minimum.
• Drink water and have a snack: fatigue and seasickness set in fast in rough seas.

Prepare the boat

• Shorten sail early: reef the mainsail (reduce its area) or furl the genoa (the headsail) before the wind builds.
• Close portholes, deck hatches, and the companionway.
• Stow and secure anything that could move, both below and on deck.
• Make sure the engine is ready to start.
• Fix your position and plot a course to the nearest shelter.

Adjust your sailing

• Stay well off lee shores (coastlines the wind is blowing toward), where you could be pushed onto the rocks.
• Choose a comfortable point of sail (your heading relative to the wind) rather than the shortest route.
• Avoid entering a narrow harbor or anchorage when the wind is at its strongest if the maneuver looks risky.
• Keep the VHF on channel 16 and listen to the forecasts.
• At anchor, let out more chain, make sure the anchor isn't dragging, and leave before the wind peaks if it's shifting onshore.

What should you do in a thunderstorm with a risk of lightning?

A thunderstorm on a sailing trip rarely lasts long, but the gusts that come before it arrive fast: it's best to get ready as soon as the sky darkens.

• In port or at anchor: stay below deck and wait for the storm to pass, usually in less than an hour.
• At sea: shorten sail before the squall hits (a sudden, violent burst of wind, often with downpours), since the gusts under a storm cloud can be sudden and violent.
• Avoid touching the mast, the shrouds (wires that support the mast), the lifelines (wires running around the deck), and any metal fittings connected to the rigging.
• Stay out of the water: no swimming and no dinghy rides during the storm.
• Unplug any non-essential electronics and keep a handheld VHF and a phone protected.
• Once the storm has passed, check the instruments, compass, and engine.

Who makes the call, depending on your type of trip?

• Skippered charter: the captain decides and you follow their instructions.
• Crewed cabin cruise: the captain decides and you follow the onboard instructions.
• Bareboat charter: you decide as skipper, in line with your contract and the base's instructions.
• Houseboat rental: you decide, following the instructions of the waterway authorities.

On a houseboat, wind mainly makes maneuvers tricky (going through locks, docking). In strong wind or a thunderstorm, the easiest option is to stay tied up until it calms down. After heavy rain, navigation may be suspended on some stretches due to flooding: the base will let you know.

Which winds should you know about at your destination?

These phenomena are seasonal trends, not forecasts: how often they occur and how strong they are varies from year to year, and only the day's marine forecast tells you what wind to actually expect.

If you're planning a sailboat charter in Greece in midsummer, factor the meltemi into your itinerary: legs heading south through the Cyclades are downwind, but the return trips north can be challenging.

Hurricanes are tracked several days in advance: if one threatens your area, the base organizes shelter for the boats and tells you what to do.

Which numbers should you call in an emergency?

On VHF, a Mayday call signals distress involving grave and imminent danger (man overboard, taking on water, fire). A Pan-Pan call signals an urgent situation with no immediate danger to life, such as engine failure close to shore. In US waters, these calls are received by the US Coast Guard; in France, by the CROSS. Both coordinate rescue at sea.

Filovent Concierge supports you throughout your trip

Monday through Friday, Filovent Concierge helps you if the weather throws off your plans: the team coordinates with the base or the crew and helps you find the right solution. On weekends, contact the base or the crew first.

• Hours: Monday through Friday, 9:30 a.m. to 6:30 p.m.
• Languages: English, French, Spanish, Italian, German.
• Phone and WhatsApp: +33 1 70 80 97 35.
• Email: concierge@filovent.com, or info@filovent.com outside business hours (checked daily).

Who should you contact first if there's a problem on site?

• Yacht charter: the base manager, whose contact details are in your customer account, under the partner contact details.
• Cabin cruise: the crew on board.
• Next: Filovent Concierge, to help you with the next steps.

If the weather causes an incident (breakdown, damage, service not as described), report it on site to the base or the crew: this report is essential for Filovent to follow up on your case.

Frequently asked questions

Are days stuck in port due to bad weather refunded?

Generally, no: weather is part of the unpredictability of sailing, and the boat remains at your disposal. Trip cancellation and trip interruption insurance rarely covers bad weather alone: check the exclusions before you buy a policy. Your Filovent advisor will help you choose the right coverage when you book.

Should you head back to the base early if the weather turns at the end of your trip?

Yes, it's recommended. If a gale is forecast for the last few days, move closer to the base ahead of time so you don't risk missing the check-out time or your flight home.

Can the captain change the planned itinerary?

Yes. Safety comes before the schedule: the skipper or captain adjusts the itinerary, stops, and timing to the weather, even if it means spending a day in port or at anchor.

How can you prevent seasickness in rough seas?

• Stay in the cockpit, in the middle of the boat, with your eyes on the horizon.
• Avoid reading or spending long stretches below deck.
• Eat light, but don't sail on an empty stomach.
• Take seasickness medication before you set out, on a pharmacist's advice.

Is a skippered charter safer in bad weather?

The captain knows the area, its shelters, and its local winds. A skippered yacht charter is the best option if you're new to sailing or heading to a region known for strong winds: the weather calls are theirs to make.