Temporali, fulmini e groppi in acqua: cosa fare

Ultima verifica: 14 ottobre 2026

Passo per passo

1. Agisci al primo segno

   Nubi scure, un aumento costante del vento o delle onde, o un improvviso salto di vento indicano che può arrivare un temporale. Se senti il tuono, sei abbastanza vicino da essere colpito. Dirigiti subito verso il porto o un riparo sicuro.[12][22][14][1][25]

2. Giubbotti di salvataggio per tutti

   Le raffiche di un temporale possono capovolgere una piccola barca. Assicurati subito che tutti a bordo indossino il giubbotto di salvataggio.[9][18]

3. Rallenta e metti in sicurezza la barca

   Riduci la velocità per mantenere il controllo. Stiva l’attrezzatura libera e fai sedere l’equipaggio in basso e al centro della barca.[18][19]

4. Su una deriva, lasca le vele nelle raffiche

   Quando arriva una raffica improvvisa, lasca il fiocco e la randa finché la barca non comincia a raddrizzarsi.[21]

5. Mettiti al riparo o stai basso

   Se la barca ha una cabina, resta dentro. Altrimenti, accovacciati il più in basso possibile al centro della barca.[2][13][10]

6. Stai lontano dal metallo e dall’acqua

   Stai lontano dalle parti metalliche e dai dispositivi elettrici, e non toccare due oggetti metallici collegati a massa contemporaneamente. Tieni braccia e gambe dentro la barca.[10][2][5]

7. Abbassa l’antenna; radio solo per emergenze

   Abbassa o lega l’antenna della radio e gli altri elementi alti se non fanno parte di un impianto di protezione contro i fulmini. Non usare la radio se non per un’emergenza.[6][16]

8. Non riesci a raggiungere la costa? Aspetta che passi

   Se non riesci a tornare a terra, lo US National Weather Service consiglia di dare fondo all’ancora e stare il più in basso possibile. I temporali di solito durano poco, quindi è meglio aspettare che passi che attraversarlo navigando.[15][3]

9. Se qualcuno viene colpito

   Chiedi subito aiuto. Una persona colpita da un fulmine non trattiene carica elettrica, quindi è sicuro toccarla e soccorrerla.[20][7]

10. Dopo il temporale, controlla la barca

    Se la barca è stata colpita, o pensi che lo sia stata, controlla che l’impianto elettrico e la bussola non siano danneggiati prima di farvi affidamento.[8]

Cosa non fare

• Non aspettare il tuono o la pioggia per rientrare. Un fulmine può colpire molte miglia davanti al temporale.[4][14]
• Non uscire se sono previsti temporali.[1]
• Non toccare più di un oggetto metallico collegato a massa contemporaneamente.[10]
• Non tenere mani o piedi in acqua.[5]
• Non usare la radio per chiacchierare quando ci sono fulmini; tienila per le emergenze.[16]

Prima di salpare

• Prima di partire: controlla le previsioni meteo marine e gli avvisi per qualsiasi menzione di temporali o groppi.[24][1]
• Prima di partire: ricorda che le raffiche possono essere più forti del 40% rispetto al vento medio previsto, e ancora di più in un temporale.[23]
• Prima di partire: pianifica una via di fuga e individua sulla carta dove puoi ripararti.[11][26]
• In acqua: continua a controllare il meteo sulla radio di bordo.[27]

Domande frequenti

Fonti

Le fonti sono citate nella lingua originale.

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.”

Altre guide alle emergenze

Numeri di soccorso per paese → Come fare una chiamata MAYDAY → Scheda di emergenza da stampare →