Trovoadas, raios e borrascas na água: o que fazer

Última verificação: 14 de outubro de 2026

Passo a passo

1. Aja ao primeiro sinal

   Nuvens escuras, um aumento constante do vento ou das ondas, ou uma mudança súbita do vento indicam que pode vir aí uma trovoada. Se ouve trovões, está perto o suficiente para ser atingido. Siga de imediato para o porto ou um abrigo seguro.[12][22][14][1][25]

2. Coletes salva-vidas para todos

   As rajadas de uma trovoada podem virar um barco pequeno. Confirme já que todos a bordo têm colete salva-vidas vestido.[9][18]

3. Abrande e prepare o barco

   Reduza a velocidade para manter o controlo. Arrume o material solto e ponha a tripulação sentada baixa e no meio do barco.[18][19]

4. Num veleiro ligeiro, folgue as velas nas rajadas

   Quando entrar uma rajada súbita, folgue o estai e a vela grande até o barco começar a endireitar-se.[21]

5. Entre ou baixe-se

   Se o barco tiver cabina, fique lá dentro. Se não, agache-se o mais possível no meio do barco.[2][13][10]

6. Longe do metal e da água

   Afaste-se das ferragens metálicas e dos aparelhos elétricos, e não toque em dois objetos metálicos ligados à massa ao mesmo tempo. Mantenha os braços e as pernas dentro do barco.[10][2][5]

7. Baixe a antena; rádio só para emergências

   Baixe ou prenda a antena do rádio e outros elementos altos se não fizerem parte de um sistema de proteção contra raios. Não use o rádio a não ser em emergência.[6][16]

8. Não consegue chegar a terra? Espere que passe

   Se não conseguir voltar a terra, o US National Weather Service aconselha fundear e ficar o mais baixo possível. As trovoadas costumam ser curtas, por isso é melhor esperar que passe do que atravessá-la a navegar.[15][3]

9. Se alguém for atingido

   Peça ajuda de imediato. Uma pessoa atingida por um raio não fica com carga elétrica, por isso é seguro tocar-lhe e ajudá-la.[20][7]

10. Depois da trovoada, verifique o barco

    Se o barco foi atingido, ou se acha que foi, verifique se a instalação elétrica e a agulha têm danos antes de confiar nelas.[8]

O que não fazer

• Não espere pelos trovões ou pela chuva para voltar. Um raio pode cair muitas milhas à frente da trovoada.[4][14]
• Não saia se houver previsão de trovoadas.[1]
• Não toque em mais de um objeto metálico ligado à massa ao mesmo tempo.[10]
• Não deixe as mãos ou os pés a arrastar na água.[5]
• Não use o rádio para conversar enquanto houver raios; guarde-o para emergências.[16]

Antes de largar

• Antes de sair: consulte a previsão marítima e os avisos para ver se mencionam trovoadas ou borrascas.[24][1]
• Antes de sair: lembre-se de que as rajadas podem ser 40% mais fortes do que o vento médio previsto, e ainda mais numa trovoada.[23]
• Antes de sair: planeie uma rota de fuga e saiba pela carta onde se pode abrigar.[11][26]
• Na água: continue a acompanhar o tempo no rádio.[27]

Perguntas frequentes

Fontes

As fontes são citadas na língua original.

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.”

Mais guias de emergência

Números de socorro por país → Como fazer uma chamada MAYDAY → Cartão de emergência para imprimir →