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

























A complete recap of the most successful Melges 20 World Championship by International Audi Melges 20 Class Association,




ISAF Santander - Upwards path for Austrian women's 470 crew + video by Luissa Smith, International 470 Class Association,


























2014 Rolex Big Boat Series - Farr 40 Day 4 by William Wagner, San Francisco












Extreme Sailing Series: Emirates Team NZ bounces back for series win
Santander 2014 ISAF Worlds - Light winds and current test six classes
ISAF Sailing World Championships - Solid Day 3 for US Sailing Team
ISAF Sailing World Championships - Day 3 images by Jesus Renedo
Marseille One Design 2014 - GC32 Armin Strom blitzes final day
Volvo Ocean Race 2014-15 - Una Etapa 0 complicada para todos
Santander 49ers: Olympic Gold Medallist says two into 90 does not go!! *Feature
GBR aiming for first ever Nacra 17 Games berth at Santander Worlds
Volvo Ocean Race: Man and sail overboard as Leg 0 serves up drama
ISAF Sailing World Championships Santander 2014 – Images by Dan Ibsen
Santander Worlds – already a spectator success
ISAF Sailing World Championships Santander 2014 - Day 3 morning report
Volvo Ocean Race 2014-15 - Tales from the extreme
Volvo Ocean Race: Latest starter wins opening race
2014 J/70 World Championship - Healy, Abdullah, Becker and Borges win
2014 Rolex Big Boat Series - Full-blown, once again
ISAF Worlds - Americans jump up Laser and Laser Radial leaderboard
2014 Rolex Big Boat Series - Farr 40 Day 3
America's Cup: Luna Rossa sailing with two foiling AC45's + Video
Extreme Sailing: Emirates Team NZ retain second overall
ISAF Sailing Worlds, Santander - Rio Olympic Laser spots snapped up   
Rolex Swan Cup - All set for final showdown   
Upper Midwest sailors need help to take it to the next level   
ISAF Sailing World Championships - RS:X action begins in Santander   
ISAF Sailing Worlds, Santander - Americans rise in Laser and Radial   
Extreme Sailing Series - A remarkable penultimate day’s racing + Video   
Marseille One Design - GC32 GDF Suez unstoppable in the light   
Rolex Swan Cup - Day 3 images by Carlo Borlenghi   
ISAF Sailing World Championships - Images of the leaders in Santander   
Rolex Big Boat Series - Good day for Double Trouble   
Rolex Big Boat Series - Day 2 images by Erik Simonson   
Royal Cup Marina Ibiza - TP52 fleet ready for tricky race tracks   
Rolex Big Boat Series - Plenty maintains lead   
2014 Asia Pacific Student Cup - Count down begins   
Extreme Sailing Series: Live coverage of Day 3 - view here   
Volvo Ocean Race 2014-15 - Going away   
Volvo Ocean Race 2014-15 - Practice makes perfect   
2014 J/70 World Championship - Contrasting conditions on Day 4   
Rolex Big Boat Series - 50 years of big boat racing: a retrospective   
2014 Rolex Big Boat Series - Day 2   


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 NEW US
LocalAds   DE  ES  FR  IT