Thread subject: Whaler Central - Boston Whaler Boat Information and Photos :: Small Boat Lightning Protection

Posted by Mike on 03/26/07 - 8:52 PM
#1

This is one of the boating hazards that, for me, comes to mind every spring. Then I conveniently put it aside.

Is it a realistic goal for folks like us to build lightning protection into our boats?

What are the procedures you follow or recommend when caught in a storm? I know we aren't supposed to have this happen to us, but it does.

Right or wrong; the thought of holding onto that SS destroyer wheel during an electrical storm makes me feel a tad bit uncomfortable.

Posted by moose on 03/27/07 - 12:29 PM
#2

Mike,
Lightning is a real and serious threat to all of us on the water. A friend of mine sells lightning dispersion equipment for offshore rigs, power plants, etc.. The truth is that they are not really feasible for small boats. I usually just go as fast as I can and stay as low as I can. I don't know if that does any good or not, but I'm still here.
Mike

Posted by danedg on 03/27/07 - 2:28 PM
#3

Moose
A single lightining bolt has enough energy to power several small cities...for a year...getting hit by one is not an option...luckily your boat is "grounded' by having the engine in the water...making it less of a target.
The best recourse is to get off the water as soon as you see weather comin'....
If you do get hit...don't worry...you won't feel a thing!

Posted by phipper on 03/27/07 - 6:44 PM
#4

I use my 13' whaler as a dingy on my houseboat. The houseboat has a grounding rod that decends into the water. Do not know if it works but it sure makes me feel better. lightening is not much of a problem in the west.

Posted by Buckda on 03/28/07 - 12:37 PM
#5

Relying on your motor as "a ground" is not a good option, because there can be sideflash that will affect the other metal components onboard (bow rails, etc) which you are in the way of...meaning, you may become a crispy critter.

Lightning bolts are measured in tens of kiloamps. Pardon the expression, but that is a hell of a lot of electricity.

I'm not sure the appropriateness to linking to other Whaler sites and how that is viewed here, but if you do a search on the "other" Whaler site, you'll find that several very smart individuals have already spent a great deal of time and energy discussing this very same topic.

Rather than recreate that information here, it's best to just look and see for yourself what they've already spent the time and energy to provide for individuals seeking this information. See: this link and this link for good discussions about lightning protection for a Boston Whaler boat.

Dave

Edited by Buckda on 03/28/07 - 2:35 PM

Posted by gfox on 03/28/07 - 4:47 PM
#6

Is it safer to be under a bridge during a bad storm? Thats where I head when I see a bad storm approaching and I'm too far from the dock. By the way Thanks so much for the site. I've been visting here for a while but this is my first post.

Posted by Buckda on 03/28/07 - 6:44 PM
#7

Click on the first link I provided in my above post. The relative protection offered by a bridge is addressed there.

Bottom line - If a bridge is nearby, chances are, so too is an opportunity to get OUT OF THE BOAT and INTO a BUILDING....I'd go for that option, if possible.

Dave

Posted by Mike on 03/29/07 - 8:45 AM
#8

Thanks all -

Dave, I agree that is good stuff on CW and it is absolutely appropriate to post links to any relevent info on any other site - even CW ;). It has been for years and continues to be one of my regular places to visit.

I see no reason not to revisit the subject on these pages. We may have different members here than there with different takes on the subject. There may be additional info that isn't included there. No problem having info on two different sites. Maybe the same basics with just a different flavor.

Edited by Mike on 03/29/07 - 8:56 AM

Posted by Buckda on 03/29/07 - 10:53 AM
#9

Okay then, and thanks for the clarification.

As to your original question about the procedures to take for lightning protection I think the best bet is to get off the water as soon as possible - even if it means leaving your boat along a seawall as you seek shelter ashore.

I don't know if lightning can hit a moving target, but I'd drop my rods, lower my antennas and full-tilt boogie as fast as possible to the nearest harbor of refuge where I could either beach the boat and get out or tie up to someone's dock or seawall and get ashore.

As to the feasibility of building a lightning protection system into a small boat like a Whaler, I think that the "heavy duty" items required would be space prohibitive, and so too would be the hassle of grounding all the metal components of the boat. Remember, you're trying to route a huge amount of electricity to ground - almost instantaneously. This requires some very heavy duty cables that offer very little resistance.

As you may or may not know, lightning actually arcs UP to the cloud. It can strike a blade of grass in the park or a towering skyscraper. There are photos on the internet that have captured the moment of a lighning strike, and you can see the tendrils of electrons streaming off nearby structures like telephone poles, etc. If you hear your antenna crackling or feel your hair get all static-y (is that a word?!), you should get as low and small as possible on your boat and don't touch anything metal. These things indicate that a strike may be iminent. I'd kill the motor too if that happened, just in case.

I'm not an expert like others, however, fortunately, it is not often that I'm faced with this problem when boating, where shelter is too far to go to beat an oncoming storm.


An average thunderstorm runs between 25-45 MPH, and the lightning can spread for miles in front of it. This is a good reason to not have the radio going in your boat. When you see lightning or hear thunder, remember to pull lines and head to shelter.

On calm seas, the average Whaler can run around 40-50 MPH at WOT, which is the throttle setting I'd recommend as you clear the area. Go as fast as you can and still get propeller bite, even if it means you're airing out the hull every few waves. Get off the water.

Also - remember - count the seconds and then divide by five between the flash and the thunder...that tells you approximately how many MILES the lightning strike is from your position. Do some fast calculus from there, given the direction of oth the storm and nearby ports.

Where you boat in SW Lake Superior, I'd say that there may be times when an oncoming storm from the West may force you to the far shore for shelter rather than run towards the storm on your way back to port.

Just a thought.

Sometimes you can out-flank a storm front, sometimes not, but the sooner you get a run on things, the better/closer to home you'll be when the doo-doo hits the fan - and in your case, perhaps you can outrun it to the far side of the lake.

Edited by Buckda on 03/29/07 - 12:05 PM

Posted by Mike on 04/25/07 - 8:30 PM
#10

Dave,

I was checking my recent threads and reealized I hadn't responded. Sorry!

Thanks for the excellent info and advice.

I remember reading the thread on ContinuousWave and had hoped the author would follow up when he was ready. But unfortunately he hasn't - that I know of.

I agree that as a practical matter building a lighting protection system for a Whaler would be less than feasible.

As near as I can remember from various sources that I've read over the last few years is that a protective "cone" needs to be created. This being done by having a grounded mast (near the operator) and high enough that 45 degree imaginary lines were drawn fore and aft from the top of the mast the lines would extend past the ends of the boat. Creating a "Faraday's Cage".

That, plus bonding it to all other metal parts like rails and such and connecting them to a large grounding plate located below the waterline on the outside of the boat
to dissipate the charge.

Not practical for our boats I guess, but an interesting topic.

Thanks,
Mike

(edited to correct information - result of my faulty memory)

Edited by Mike on 04/26/07 - 3:52 AM

Posted by Mike on 04/26/07 - 3:58 AM
#11

Here are some reference articles for those of you interested in this subject.

http://www.kastenmarine.com/Lightning...htning.htm

http://www.setsail.com/_storefiles/69...es/69.html

http://www.marisafe.com/news/articles...e=1&aid=81

http://www.cdc.gov/nasd/docs/d000001-...00007.html