R 22

Rhodes 22



The current issue of SAIL has an article about lightning protection. There has been some discussion of this on the Seaward list. A couple of people have talked about clipping battery jumper cables to one or more chainplates and dragging the other end overboard. I've also heard that, but the article gets pretty specific about cabling the mast to the keel with #4 copper wire.

If I remember, the Rhodes lead keel is actually inside the fiberglass hull, so grounding to our keel wouldn't be very effective. The article also talks about attaching a 1 sq ft copper plate to the bottom below the water line (larger if you're in fresh water) and grounding the mast to that. I don't like the idea of drilling holes in the bottom of my boat.

Anyone have experience with lightning and/or grounding schemes?

Gary Sanford
23 Jul 1998

I have been wondering about lightning and my boat for some time. The first problem I discovered is that lightning and boats in not well understood. With lightning in general not under stood. There seems to be two general thoughts about the subject. Have the best path to ground or have no path to ground. If you are going with the best "route" you want high surface area heavy flat straps (1-4 inches) with a straight line (no bend or turns) into large grounding plates. The other answer seem to have no path to ground making the boat a poor target, the Rhodes22 uses the latter, there are no paths to ground for any of the rigging/mast. The only ground is the outboard motor on the boat.

It seems from the anecdotal stories about lightning and boats is that boats that seem to get into trouble have keel-stepped masts without the ground plate. The lightning might blast right through the hull to get to ground. Also, boats that have done something, but not the complete job (small plates, small wire, bends or turns etc,). I am not an expert and I do not know if there is an answer. Lightning strikes are rare, lightning strikes on boats are rarer. The bottom line is it seems that no one knows.


The closest call I've ever had with lightning was in July 1993 at Seaway Marina on Kelly's Island in western Lake Erie. My 2 sons and I were cruising the western end of Lake Erie. We lived on the boat for 6 days. The marina was crowded; but we'd been lucky enough to get one of the slips up against the shore side wharf almost right in front of the marina store. Boats were rafted off two and three deep.

About 2:00 AM, a thunderstorm rolled thru. We were all violently awakened by a blinding flash with a simultaneous KABOOM!!! There was a heavy smell of ozone in the air and the hair was standing up on the back of my neck from the static in the air despite nearly 100% humidity. The EMP from the lightning bolt knocked out all the electrical power in the marina and set off the burglar alarm in the marina store (I suppose it had a battery back-up). So, it was pitch black with no onshore lighting and the burglar alarm was blasting just 20 yards away. It was several minutes before the owner, who lived in an apartment behind the store, shut off the alarm. As soon as I woke up, I lifted the privacy curtain on the starboard side pop- top window and could see the faint outline of a mast glowing dull red in the darkness. Lightning had struck the mast of a sailboat about four slips down.

The boys and I threw on some clothes, I grabbed my handheld VHF radio, and we went and stood under the awning of the store. It wasn't raining or blowing particularly hard. That was the only lightning strike on Kelly's Island that night, although we saw frequent cloud to water lightening strikes for several minutes. The next day, we saw the boat that had been struck was a Beneteau 40-foot center cockpit sloop. The mast was bent about 15 deg just above the upper spreader, the masthead VHF antenna and wind speed/direction sensor had been vaporized, and every piece of electronics on the boat was toast. There was no hull damage and no one had been injured.

Roger Pihlaja
S/V Dynamic Equilibrium

There was a popular brand boat (not Catalina) that was hit by lightning while on a mooring ball on Navajo Lake. When the owner returned to his boat, it was sinking. Seems the lightning dissipated its energy by blowing millions of tiny holes through the fiberglass and gelcoat -- very small holes that leaked. The boat was sent to California for repair and a major overhaul of the hull was done.

Alex Bell

West Marine will send you a free packet of articles about lightning.

Included in the material are some interesting statistical studies about how lightning damages boats. In summary, sailboats are more likely to be hit than powerboats. Boats near shore or docked are more likely to be hit than boats on the open water. Boats on salt water are more likely to be hit than boats on fresh water.

The physics of it is that if your boat is in a lower voltage area between sky and earth surface, the likelihood of getting struck is higher.

Boats with lightning protection on open salt water suffer only slightly less damage from lightning strikes than boats without lightning protection, but the people aboard fare better. Boats on open fresh water pretty much always get sunk when they are hit, but here again lightning protection helps the people.

I had a sailboat boat hit at the dock in brackish water. I know because I had an anchor chain shackled to a stay and the fiberglass next to the chain was charred. No other damage.

Since I'm mainly a fresh water sailor, I have extended my experience with the chain to try and protect the people in the boat if I get hit. I have 5 battery cables for clamping to the two aft stays, the fore stay and to the port and starboard sides of the mast. I hope the cables with their frayed ends will ground most of the strike into the water leaving the crew untouched. However, I expect there is still the likelihood that much of the strike will jump from the base of the mast, through the cabin and out of the bottom of the hull, filling the Rhodes with water.

Fred Lange

The best system I know is to park your boat next to a boat with a taller mast. And hope he is grounded.

Steve Little

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