Ten Tips to prepare for a lightning strike on a sailing boat

by BoatUS Seaworthy Magazine on 30 May 2011 Lightning strikes are one of the possibilities that bring fear to the heart of even the most experienced of sailors. While a storm at sea may bring difficult conditions from wind and sea state, the experienced sailor has a range of techniques for avoiding disaster. However, lightning is another story.

BoatUS' Seaworthy Magazine recently took a look at how to protect yourself from this hazard on a wide variety of sizes and types of boats, and has these tips:

1• Don't wait until it's too late: Get off the water early: Getting to safe harbor is the safest bet. If you're in a powerboat and can't get in, you may be able to get around the storm.

2• Inside is best: If you can't get off the water in time, the best place to be on a boat is inside any cabin, but avoid being near mast or chainplates, or large metal appliances like refrigerators.

3• Disconnect the power and antenna leads to your electronics: Many strikes just damage electronics so disconnecting them goes a long way in preventing equipment damage.

4• Keep away from metal: If there is no 'down below' and you're stuck out on deck, stay away from metal railings, wheels, the mast and mast stays, or any other metal fittings. There is record of a boater being killed in North Carolina when lightning jumped from his sailboat's backstay to his head and then the metal steering wheel he was holding.

5• Don't be a lightning rod: If you're on an open boat, stay low and in the center. Depending on the severity of your situation, it's also a good idea to remove jewelry. There was a case reported a few years ago in which lightning struck a man who was standing up wearing a large medallion.

6• Stay out of the water: Don't fish during a thunderstorm - or dangle toes overboard.

7• Lower antenna: Unless they serve as part of a lightning protection system, lower any antennas.

8• Stay silent: Don't use the VHF unless absolutely necessary.

9• Lightning grounding protection systems: Grounding systems, which provide a path for the lightning to enter and safely exit the boat, must be free of corrosion if they are going to provide any protection.

10• Dissipater dilemma: As for mast-top lightning dissipaters, there is no agreement by the experts on how well or if they work at all. It should be noted that BoatUS insurance claims files show that boats with 'brush-like' dissipaters mounted at the top of the mast have been struck by lightning.

Finally, if you do get hit:
1) Check people first
2) Then check the bilge as strikes can rupture through-hull fittings and punch holes in hulls
3) Check electronics and compass
4) You may want to consider a short haul to check the bottom thoroughly (trailerboats can be inspected when you get back home). The challenge with lightning strikes is that they sometimes leave hard to find traces of damage that may only be seen when the boat is out of the water.

Seaworthy, the magazine:
Published four times a year by BoatUS Marine Insurance, Seaworthy's pages are filled with case studies that provide insight into how to avoid accidents, breakdowns, injuries and the 'unexpected' circumstances that can jeopardize the safety of your boat and guests. Annual subscriptions are available for $10 at www.BoatUS.com/seaworthy. For a free online insurance quote, go to www.BoatUS.com/insurance or call 800-283-2883.