sail-world.com
 
 
News Home Cruising Photo Gallery Video Gallery
Sail-World.com : Lightning at sea: Myth and Reality
Lightning at sea: Myth and Reality

'Lightning - unavoidable if you are already at sea'    .

Lightning strikes, like collisions with whales or floating containers, cannot be planned against if you are already at sea, and thunderstorms are among the most violent forces of nature. Here Des Ryan separates fact from fiction.

At sea, it is possible to encounter squall line thunderstorms that have developed over land. Thunderstorms that form at sea occur most often in the early morning around dawn. However, tropical thunderstorms can occur at any time, often daily because of intense heating over land and an unlimited supply of moist tropical air from the ocean.

Thunder is the result of a lightning bolt. Lightning is a large current for a short period of time (milliseconds). This is a danger on an unprotected boat. Lightning can vaporize antennas, destroy electrical power, navigation systems, blow a hole in the hull or start a fire.

The theory of what happens when a sailing boat with lightning protection receives a strike - the conductor guides the lightning through a preferred path to the keel -  .. .  
Cruising friends who have experienced a lightning strike aboard their boat have agreed on one thing - the strike was so severe that no normal lightning protection would have worked, as the electricity was so powerful that it jumped through the air to reach metal objects, sometimes as far as 20 cm.

However, this is anecdotal evidence, and who knows how much worse the strike would have been had these boats not had lightning protection. To equip your boat with lightning protection, the following system needs to be installed: A sharp pointed rod (lightning rod) at the top of the highest point of the boat has to be connected with a good conductor of electricity. On sailboats, the mast can be used if it is made of metal. From the rod or mast, run a heavy copper wire (8AWG) to a metal keel. This wire should be run straight, without sharp bends. All connections need to be mechanically strong. The metal keel plate needs to be through-hull bolted and in good electrical contact with the water.

The theory is that the properly grounded mast (lightning rod) will provide a cone of protection. The point of the rod should extend at least 6 inches above everything it is to protect. The cone then makes roughly a 60-degree angle with the vertical, and the circle of protection at waterline has a radius of 1.5 to 2 times the height of the lightning rod. If all of the boat is within this cone, you are protected at least 99 percent of the possible strike. Within 45 degrees, the protection is 99.9 percent.

However, if you are caught in a thunderstorm, have everyone stay in the center of the boat. If you have a hand-held VHF or GPS, put it in a microwave if you have one. If not, separate it by a wide distance from anything metallic. Don’t let anyone go into the water. Stop fishing. Do not touch or go near anything metallic.




Here are some of the common myths attached to lightning:

Myth 1: Lightning does not strike the same spot twice:

It is a myth that lightning does not strike the same spot twice. In a typical lightning flash, several strokes may hit the same spot in rapid succession. This is proven by the fact that tall structures are sometimes hit many times a year.

Myth 2: There is no danger of being hit by lightning if it is not raining:
It is a myth that if it is not raining there is no danger of being struck by lightning. Lightning bolts can and often do strike as much as ten miles outside of the rain area of the main storm. Recent research on lightning deaths finds that most fatalities occur in the period when the storm appears to be ending.

During the height of most thunderstorms, sailors are below anyway, seeking protection from the rain. For the ten or more minute period after the rain ends, and even after the sun comes out, lightning is still a threat. Lightning can be a threat as the storm approaches as well. The storm may be a good distance away and may have blue sky overhead. A lightning strike would still be possible.

Myth 3: If you touch a lightning victim, you’ll be electrocuted:
The truth is that the human body does not store electricity. Therefore, it is safe to touch a lightning victim and give them first aid.

Myth 4: If you are on shore and lightning is about to strike, lie flat on the ground:
The best thing to do in that scenario is to crouch down, ie, put your feet together, squat low, and tuck your head. Lightning induces electric currents along the top of the ground that can spread out and be deadly over 100 feet away. While lying flat does get you low, your chances of getting hit by ground currents are increased. You want to be as low as possible but also touch as little ground area as possible. Obviously, getting inside to proper shelter would be even
better.

For a worthwhile technical description of the interaction between lightning and sailing boats by the University of Adelaide, click here.


by Des Ryan

  

Click on the FB Like link to post this story to your FB wall

http://www.sail-world.com/index.cfm?nid=103074

12:08 AM Mon 22 Oct 2012GMT


Click here for printer friendly version
Click here to send us feedback or comments about this story.


Related News Stories:

22 Oct 2012  Skill Building at the CYCA - Cruising to Hobart
20 Oct 2012  Cruising Preparation Seminars: Mackay, Brisbane, Newcastle, Hobart +
20 Oct 2012  Sailing Navigation Secrets - How to Pass Through a 'Flashing Gate'
10 Oct 2012  How to predict combination afternoon breezes
21 Sep 2012  Seven annual sailing season inspections to save you money!
17 Sep 2012  Singapore Sailing Federation: Sail in the City
15 Sep 2012  Classic Asymmetric Sail Mistakes - And How to Avoid Them
26 Jul 2012  Loving your dinghy - Tips in dinghy dexterity
25 Jul 2012  Flotilla Sailing Holiday increases the sailing skills
23 Jul 2012  Boat Docking Classic event attracts the champions
MORE STORIES ...






News - USA and the World







International Moth Worlds - Mothballed on day 4 + Video by Mark Jardine / YachtsandYachting.com,




Gladwell's Line: A change of direction needed in the America's Cup *Feature by Richard Gladwell/Sail-World.com/nz,
























Anna Tunnicliffe set to compete at the CrossFit Games by Anna Tunnicliffe, Pittsburgh, PA
























Final day shakes up standings at Cape Panwa Hotel Phuket Raceweek by Cape Panwa Hotel Phuket Race Week 2014,








2014 Cape Panwa Hotel Phuket Raceweek - Waiting game on Day 3
International Moth Worlds: Thunderstorms delay racing on Day 1
Fuerteventura World Cup - Impressive tricks on day 1
2014 Governor's Cup - Two former winners in the finals
America's Cup: Iain Murray explains reasons for Australian withdrawal *Feature
Wilson and Roble remain number one match racers in U.S.
2014 ISAF Youth Match Racing World Championship - Set to start
PWA Pozo World Cup - Moreno twins dominate home spot
ISAF Youth Worlds - Record breaking regatta in Tavira + Video
Melges 32 European Championship - Robertissima remains out front
Farr 40 West Coast Championship - Italians take one-point lead
Melges 32 European Championship - Day 3 images by Carlo Borlenghi
New York Yacht Club Race Week - Marstrom 32 fleet off to anxious start
Melges 32 European Championship - Day 3 images by Max Ranchi
CYC Race to Mackinac - Cruising fleet sets sail in 106th edition
Team Alvimedica getting a touchup
PWA Pozo World Cup - Plenty of drama on day 5
ISAF Youth Sailing World Championship - Day 5 Videos
NYYC Race Week - High performance classes put on shoreside show
2014 Pacific Cup - 'Invisible Hand' the first boat to finish
Clipper Round the World Yacht Race - B.C.'s Eric Holden skippers wins   
America's Cup: Updates on Team Australia withdraw   
J/70 North American titles - Brian Keane moves to top of leaderboard   
2016-2017 America's Cup - Team Australia withdraws   
VX One North American Championship - Chris Alexander takes charge   
America's Cup: Team NZ disappointed, but on track after Australians go   
America's Cup: Hamilton Island decides not to proceed with Challenge.   
America's Cup: Challenger of Record withdraws from Regatta   
WWA Wakeboard National Championships head to Waco   
Farr 40 West Coast Championship - Day 2   
RP52 Scarlet Runner sails in San Francisco   
2014 Governor's Cup - Nevin Snow and team on form   
ISAF Youth Worlds - Americans claim silver medals in Tavira   
2014 Cape Panwa Hotel Phuket Raceweek - Day 1   
Melges 32 European Championship - Day 2 images by Carlo Borlenghi   
Windsurfing and Kiteboarding World Cup to take place on Fuerteventura   
ISAF Youth Worlds - Medals decided in thrilling Tavira conclusion   
7th Annual Swim for Cystic Fibrosis to take place July 21st   
Melges 32 European Championship - Day 2 images by Max Ranchi   
Cape Panwa Hotel Phuket Raceweek, Day 2 - It just keeps getting better   


For this week's complete news stories select    Last 7 Days
   Search All News
For last month's complete news stories select    Last 30 Days
   Archive News







Sail-World.com  


















Switch Default Region to:

Social Media

Asia

Australia

Canada

Europe

New Zealand

United Kingdom


http://www.sail-world.com/event_images/image/Twitter_logo_small.png http://www.sail-world.com/event_images/image/FaceBook-icon.png  http://www.sail-world.com/event_images/image/RSS-Icon.png

United States

Cruising Northern

Cruising Southern

MarineBusiness World

PowerBoat World

FishingBoating World

 

Contact

Commercial

News

Search

Contact Us

Advertisers Information

Submit news/events

Search Stories/Text

Feedback

Advertisers Directory

Newsletter Archive

Photo Gallery

 

Banner Advertising Details

Newsletter Subscribe

Video Gallery

Policies

 

 

 

Privacy Policy

 

 


Cookie Policy

 

 



This site and its contents are © Copyright TetraMedia and/or the original author, photographer etc. All Rights Reserved.  Photographs are copyright by law.  If you wish to use or buy a photograph contact the photographer directly.
XLXL WAS US
LocalAds   DE  ES  FR  IT