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Aikensail 10-22-2013 12:26 AM

Lightning protection- precision 18
I just bought a used Precision 18 and was wondering what is the simplest way to install lightning protection? I have very few electronics aboard as it's so small- VHF, am/fm radio, depth finder and gps. It's all attached thru the fuse panel directly to the battery. I really worry about the mast obviously.


trantor12020 10-22-2013 01:04 AM

Re: Lightning protection- precision 18
A simple enough way is to fit a 24V Zener diode across the 12V supply of the electronic device (as close to the device). Do observe the polarity of the Zener. Cathode to plus and Anode to minus.

boatpoker 10-22-2013 06:31 AM

Re: Lightning protection- precision 18
60,000,000volts discharging 60,000amps, hotter than the surface of the sun and travelling at near the speed of light is going wherever it wants no matter what you do.

Anything you do will be based on "theory" ... in "theory" everything works.

trantor12020 10-22-2013 07:16 AM

Re: Lightning protection- precision 18
Last I checked, nothing in this world could take a direct lightning hit. The zener is meant to snub any transient or induced current/voltage picked up by wirings. The idea is that if the positive wire get lifted above 24V, the zener would zap it down. If the negative line voltage gets lifted, the zener conducts like a diode, zapping the surge voltage. One may argue that the surge voltage slew rate is so fast that the diode may not responds fast enough, well its cheap and easy but offers no guarantee, still better than not doing anything.

Dog Ship 10-22-2013 08:06 AM

Re: Lightning protection- precision 18
Park it next to a boat with a bigger mast. In all likelihood the lightning will hit it before you.

trantor12020 10-22-2013 11:09 AM

Re: Lightning protection- precision 18
great idea. co-incidentially, my new stereo got fry in a lightning storm 2 weeks ago. i fitted a vhf-fm splitter on the vhf antenna. i think the surge came thru that and fry my stereo. my boat was between two larger boats with taller mast. well i don't know if there's any damage to the other 2 boats as their owners weren't around. now i use internal antenna for the stereo. all my other electronics survived, including the vhf. i can't say the zeners saved the day. who knows. perhaps if i check each one to see if they are still working. if they still works then it doesn't confirm anything. if any zener fails, then perhaps it does its job.

manatee 10-22-2013 12:04 PM

Re: Lightning protection- precision 18

DonScribner 10-22-2013 12:28 PM

Re: Lightning protection- precision 18
1 Attachment(s)
Lightning Protection and other myths.

That should get folks talking.

I have read a few articles on this topic. Some swear by it, others scoff at it. The lightning protection industry waffles on its effectiveness as does the insurance industry. SO, the real question is "What is the likelihood that you will take a strike?" Answer that and you'll find out whether on not you should spend the money. If I recall correctly, south Florida is lightning strike alley, with 20% of the boats taking hits or near misses. Up here in Maine, I've only heard of one fellow taking a near miss that still fried his electronics. There may be more that I haven't heard about. The real problem isn't the electronics but a blow through in the hull. The lighting can burn a hole right through as it exits. If it's someplace that you can see, plug it. But if it exits in the back of the transom where you cant' see or reach, you're pretty much done. Terror tactics notwithstanding, I wouldn't worry about it. A 20' mast isn't very likely to get hit. But, again, check your location. Our mast is about 30' up and I'm not terribly concerned.


trantor12020 10-23-2013 03:41 AM

Re: Lightning protection- precision 18

Originally Posted by manatee (Post 1108969)

It would seems there're more golfers being killed by lightning than sailors. So sailing is safe. ...relatively speaking. :laugher

cruisingdream 10-23-2013 08:07 AM

Re: Lightning protection- precision 18
place boat in a Faraday cage.

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