Thunderstorms, lightning and squalls on the water: what to do

Last verified: 14 October 2026

Step by step

1. Act at the first sign

   Dark clouds, a steady rise in wind or waves, or a sudden wind shift mean a storm may be coming. If you can hear thunder, you are close enough to be struck. Head for port or safe shelter straight away.[12][22][14][1][25]

2. Lifejackets on everyone

   Gusts from a thunderstorm can capsize a small boat. Make sure everyone on board is wearing a lifejacket now.[9][18]

3. Slow down and secure the boat

   Reduce speed to keep control. Stow loose gear and have the crew sit low and in the middle of the boat.[18][19]

4. In a sailing dinghy, ease the sails in gusts

   When a sudden gust hits, release the jib and mainsail until the boat starts to come upright.[21]

5. Get inside or get low

   If your boat has a cabin, stay inside. If not, crouch down as low as you can in the middle of the boat.[2][13][10]

6. Keep away from metal and the water

   Stay clear of metal fittings and electrical devices, and don't touch two grounded metal objects at the same time. Keep arms and legs inside the boat.[10][2][5]

7. Lower the antenna; radio for emergencies only

   Lower or tie down the radio antenna and other tall fittings if they are not part of a lightning protection system. Stay off the radio unless it is an emergency.[6][16]

8. Can't reach shore? Wait it out

   If you cannot get back to land, the US National Weather Service advises dropping anchor and getting as low as possible. Thunderstorms are usually short, so waiting one out is better than riding it out.[15][3]

9. If someone is struck

   Call for help immediately. A person struck by lightning carries no electrical charge, so it is safe to touch and help them.[20][7]

10. After the storm, check the boat

    If the boat was struck, or you think it was, check the electrical system and the compass for damage before relying on them.[8]

Don't

• Don't wait for thunder or rain before heading in. Lightning can strike many miles ahead of the storm.[4][14]
• Don't head out if thunderstorms are forecast.[1]
• Don't touch more than one grounded metal object at the same time.[10]
• Don't trail hands or feet in the water.[5]
• Don't use the radio for chat during lightning; keep it for emergencies.[16]

Before you sail

• Before you go: check the marine forecast and warnings for any mention of thunderstorms or squalls.[24][1]
• Before you go: remember gusts can be 40% stronger than the forecast average wind, and stronger still in a storm.[23]
• Before you go: plan an escape route and know from your chart where you can shelter.[11][26]
• On the water: keep checking the weather on your marine radio.[27]

Frequently asked

Sources

1. US National Weather Service (NOAA) (2026-10-14): “It is therefore strongly recommended you do not venture out if thunderstorms are a possibility. If you do venture out and recognize thunderstorms nearby, head to port or safe shelter as quickly as possible.”
2. US National Weather Service (NOAA) (2026-10-14): “If your boat has a cabin, then stay inside and avoid touching metal or electrical devices. If your boat doesn't have a cabin, stay as low as you can in the boat.”
3. US National Weather Service (NOAA) (2026-10-14): “Keep in mind that thunderstorms are usually brief so waiting it out is better than riding it out.”
4. US National Weather Service (NOAA) (2026-10-14): “Stop all activities when there is lightning or when weather conditions look threatening. The first lightning strike can come out of a clear blue sky many miles ahead of an approaching thunderstorm cloud.”
5. US National Weather Service (NOAA) (2026-10-14): “Keep arms and legs in the boat. Do not dangle them in the water. Water conducts electricity from lightning.”
6. US National Weather Service (NOAA) (2026-10-14): “Lower, remove or tie down the radio antenna and other protruding devices if they are NOT part of a lightning protection system.”
7. US National Weather Service (NOAA) (2026-10-14): “Victims do not carry an electrical charge after being struck.”
8. US National Weather Service (NOAA) (2026-10-14): “If a boat has been struck by lightning, or is suspected of having been struck, check the electrical system and the compasses to ensure that no damage has occurred.”
9. US National Weather Service Melbourne (NOAA) (2026-10-14): “If a thunderstorm threatens while afloat, be sure everyone aboard is wearing a life jacket as a small boat can be overturned by gusty winds.”
10. US National Weather Service Melbourne (NOAA) (2026-10-14): “If lightning is threatening, keep below decks if possible; keep away from metal objects that are not grounded to the boat's protection system; don't touch more than one grounded object at the same time.”
11. US National Weather Service Melbourne (NOAA) (2026-10-14): “Have an escape plan in mind. Thunderstorms and weather related hazards form quickly. Never let these storms cut off your route back to land.”
12. US National Weather Service Melbourne (NOAA) (2026-10-14): “Dark, threatening clouds usually foretell the approach of severe weather. Other things to watch for are a steady increase in wind or seas or an increase in wind opposite in direction to a strong current.”
13. US National Weather Service Miami (NOAA) (2026-10-14): “Get out of the water, off the beach and out of small boats. If caught in a boat, crouch down in the center of the boat, away from metal hardware.”
14. US National Weather Service Miami (NOAA) (2026-10-14): “Remember, if you can hear thunder, you are close enough to the storm to be struck by lightning.”
15. US National Weather Service (NOAA) (2026-10-14): “If you are out and cannot get back to land and safety, drop anchor and get as low as possible.”
16. US National Weather Service (NOAA) (2026-10-14): “Remember to stay inside the cabin and away from any metal surfaces. Stay off the radio unless it is an emergency!”
17. US National Weather Service (NOAA) (2026-10-14): “Wait 30 minutes until after the last rumble of thunder before going back to the beach.”
18. Coastguard New Zealand (2026-10-14): “If you’re close to shore, consider heading back early. If you’re further out, reduce speed, secure loose items, and ensure all passengers are wearing lifejackets if not already.”
19. Coastguard New Zealand (2026-10-14): “Stabilise your boat by stowing loose gear and get your crew to sit low and in the middle of the hull to further improve stability and safety, especially in smaller boats.”
20. Coastguard New Zealand (2026-10-14): “And lastly, if you are in danger, call for help. Don’t risk a fatal event, as your pride got in the way of radio CH16.”
21. Transport Canada – Rental Boat Safety Checklist (Sailing Dinghy) (2026-10-14): “Release the jib and main sail until the boat starts to flatten out when there are unexpected gusts of wind”
22. Australian Bureau of Meteorology (2026-10-14): “sudden increase in wind speed or change in wind direction”
23. Australian Bureau of Meteorology (2026-10-14): “Forecasts show average wind speeds. Wind gusts can be 40% stronger than the average wind speed and even stronger during a storm.”
24. Australian Bureau of Meteorology (2026-10-14): “Check for mention of thunderstorms or squalls, as this may indicate strong winds could develop faster.”
25. Transport Canada – Safe Boating Guide (TP 511E) (2026-10-14): “Summer thunderstorms can strike quickly and without warning. Keep your eye on the sky when you’re out on the water. If it starts to look dark and cloudy, and conditions are changing quickly, head for shore.”
26. Transport Canada – Safe Boating Guide (TP 511E) (2026-10-14): “Remember to check your up-to-date nautical charts in advance so you’ll know where to find shelter.”
27. Transport Canada – Safe Boating Guide (TP 511E) (2026-10-14): “If you have a marine radio, you can get weather updates while you’re on the water.”

More emergency guides

Rescue numbers by country → How to make a MAYDAY call → Printable emergency card →