It’s one of my biggest fears at sea…. streaks of electricity aiming for the highest thing in the ocean – our mast!
Here’s some tips to help prevent damage and other precautions to take:
Your *oven (or microwave) is a good temporary *‘Faraday cage’ for protecting equipment during a lightning storm. (Faraday cages shield their contents from static electric fields.) During a lightning storm ensure you disconnect your equipment, flicking off a circuit breaker is not enough if you are hit. If you have put your equipment in the oven, don’t forget to remove it before next using the oven or microwave!
In a serious electrical storm, the following is recommended:
Stay below decks (bear in mind to keep a good watch if at sea; the regulations state that ‘Every vessel shall at all times maintain a proper lookout by sight and hearing as well as by all available means appropriate in the prevailing circumstances and conditions so as to make a full appraisal of the situation and of the risk of collision’).
Stay away from the mast, boom, shrouds, chainplates, the mast compression post and mast below decks.
Plot your position and turn off all your electronic equipment.
Be aware of the set and drift so you can do a DR (deduced reckoning) if you have to. (See Navigation section.)
Do not operate radios unless in an extreme emergency.
Lightning storms are usually short lived.
If you suffer a strike:
Check your through-hulls (if they are metal) for any discoloration in the fibreglass or other signs of damage associated with the strike.
Check for electrical damage and check your rigging. Double check your compass, it may have been affected.
Protection: There are lightning protection devices which some people like and others do not. Research your circumstances and see what suits your situation and set up best.
Indirect hit: A lot of damage can be suffered from an indirect hit; a nearby boat or buoy could be hit and the charge can transfer through the water to other vessels.
No GPS or Radio: It will pay to be able to navigate by chart and deduced reckoning; you may have no electronics and no way to radio for help.
Insurance: If you are insured, after a lightning strike call your insurance company at the first opportunity and follow instructions. It will probably mean a haul out and/or inspection.
Excerpt from Cruisers’ AA – now available for around $3.99 (US) on Kindle!
*A Faraday cage is a metallic enclosure that prevents the entry or escape of an electromagnetic field.
*The oven needs to be the type without glass (ie all metal, so a metal door). Please note, this is advice we have taken, and have no actual ‘proof’ it works! – It certainly made us feel better during a lightning storm.