I see the popularity of camping aboard small boats, or “dinghy cruising,” across the internet. (There is a even a “dingy cruising association.”) I love the idea, so I began designing a tent and sleeping platform for my Jimmy Skiff. Then it hit me that the purpose of the tent I was designing was to keep out rain, and rain often means lightning, and lightning in a small boat sounds dangerous.
So how dangerous is boating in the rain and lightning? If it is dangerous, why have a tent on board?
In the rain is no danger at all. Mosquitos are worse. It's the lightning that's the problem.
That said, the tent is not what attracts the lightning, it's that mast that's sticking up out of the water higher than anything else around.
When I go boat camping in my Faering Cruiser, I always check the weather first and skip the trip if it looks as if there's going to be a thunderstorm. There's 2 kinds of thunderstorms in the Chesapeake area - storms caused by a frontal passage and summertime afternoon pop-up thunderstorms. It's similar in other parts of the country, but with some variation near mountains.
The frontal passage ones are pretty easy to avoid. The weather service is good about predicting them and is usually never more than a day wrong either way about the timing (and usually not that). The summer afternoon storms are a bit more hit-and-miss, but with some practice you can learn to tell when they're coming. You're basically looking for a hot, humid hazy day with puffy white clouds (cumulus) growing taller and much larger and getting anvil-shaped (turning into cumulonimbus). It usually takes till around 4:00 pm in the afternoon for them to start thundering.
So, as a practical matter, avoid the water during frontal passages and on hot hazy humid summer days get off the water by 4:00 pm and you should be fine. Keep your eyes open and learn to read the sky. If you're going to be caught in a storm, go ashore. That way you won't be the tallest object in a large flat area.
Have fun,
Laszlo
If you can find a snug cove with banks higher than you, you might have better luck dodging the lightning strikes. I believe it helps to keep "prayed up" as well.
I cruised in my Sea Pearl 21 (mast vertical clearance about 20', aluminum masts, "soft-top" canvas cabin) for many miles over many years, in all sorts of weather, including some thundersqualls which just weren't avoidable. So far, so good, even with The Curse of Scheibeck working against me. <;-) Your mileage may vary, of course....
.....Michael
Never in over 40 years in and around small open boats, and nowhere in my vast library of small boat magazines and books, have I ever heard of a SINGLE case of lightning striking a small boat while in use on the water. Not once. Neither in open water nor close ashore.
OF COURSE it could happen, but I think the odds are similar to being struck by lightning while undertaking ANY sort of outdoor activity. Which aren't zero but are very low. Whenever I'm cruising in a small boat, I'm going to moor someplace protected, probably in a cove surrounded by trees or alongside boats with masts that are higher than mine. I figure that at that point, my chances are probably better than someone playing golf. And even if the boat does get hit, you might just get a tremendous scare.
I've had personal experience with three cases.
1. A CLC Jimmy Skiff was stored in a backyard here in Annapolis with its mast stepped. Not on the water, nobody aboard. The impact blew the mast step out of the boat. No one was hurt, and we still have the dislodged chunk of the hull hanging on our wall here. The boat was repaired.
2. I was helping with the post-strike survey of a large yacht. Basically the lightning had roached the electronics. No one hurt. There were several very small "exit wounds" in the fiberglass hull of the ~45-foot sailboat, none even large enough to have caused a leak.
3. I was working at a marina when a violent Chesapeake thunderstorm swept through. I retreated to my car. A sailboat a few hundred yards away in a slip was hit. No one was aboard. It started a small fire in the boat's electrical panel, which went out before the fire engines arrived. Other than electrical damage I'm not sure what else happened.
Speaking of larger boats, I'm in the camp that thinks that adding "lightning protection," in the form of an aerial on the mast wired to grounding plates on the hull, is about as useful as the anti-elephant powder I've been spreading in my front yard all these years.
Jerry Powlas, of Good Old Boat Magazine, had the best writing on the subject of sailboat lightning strikes I've ever found, in the aftermath of a strike on his own boat. (The article itself doesn't seem to be online, alas.)
My two favorite pull-quotes, vis-a-vis lightning protection for a small sailboat:
"My concept of conductors and insulators was not useful at the very high voltages involved. I suspect when you are dealing with a voltage so high that the strike has already come thousands of feet though air, there may be no resistors, just conductors of varying resistance."
In other words, if lightning chooses YOU, your patented lightning protection isn't worth a bucket of spit.
And:
"I will decline comment on acts of God, which may be an unfortunate term. We were on board when the lightning hit. Actually we were showering. There is an arrogance in that, but we survived.
It is very difficult to separate true scientific understanding from promotional claims and the folklore. I suspect many of the cures and fixes work because the boats are not hit. Anything works if the boat is not hit. Perhaps very little works if it is hit. I am convinced that if the boat is hit, no matter how the boat is configured, all or almost all of the electronics will be destroyed."
I'd call that a mic-drop on the subject.
Nice discussion by John.
I worked as a system safety engineer for a number of years. This is not my area of expertise, but a web search shows that the odds of being struck by lighting in the USA is about 1/700000 per year. Being on a sailboat probably raises that a bit. The odds of being killed in a car accident in a year is about 1/5000. So basically, you are 100 times more likely to be killed driving to go sailing than by lightening while sailing.
I'm with John on this one. How did he come to be so smart? <;-)
The only lightning-to-boat strike of which I have a first-hand account was by a couple sailing a Sea Pearl 21 in Tampa Bay in midsummer (the epicenter of violent lightning, I'm told). The mainmast (the forward mast of a cat-ketch) was struck, blowing a hole in the bottom of the boat and setting the fiberglass afire. They were able to get the fire out (Class A fire, plenty of water available), stuff enough stuff in the hole to slow the ingress of water, and then sail the boat aground on a beach not too far away. The biggest problem they had was communicating with each other throughout the business. The thunderclap rendered them temporarily deaf.
.....Michael
Something being tall does not encourage a strike. A lightning rod is NOT designed to be the designated hit, it PREVENTS a strike by preventing a build up of electrons, by being connected to a ground. When that ground is not maintained, it THEN becomes a designated hit. This presumes your grounding system can ground out electrons faster than something else nearby, it can be overwhelmed and get hit anyway...
The mast on any boat should be connected to a anode below the waterline.
A properly installed ground will keep you as safe as your gonna be. However, camping in a boat during a storm sounds dicey...
Mike
Thanks for the eager and informative responses. Seems to be a "charged" topic.
John, thanks for bringing your wealth of experience to bear. I work in an industry where folks sometimes use fancy lightning protection products on outdoor storage tanks, and our joke is that the products "always work, unless they get hit."
Here's what I'm hearing:
1.) Tents are useful for multiple reasons: mosquitos, privacy, dew, and obviously rain. So there are good reasons for a tent even if you avoid storms.
2.) Proper planning reduces the need for a weekend sailor to worry about lightning.
3.) If you do find yourself on the water during a storm, rest in the knowledge that the odds of getting hit are incredibly small... possibly higher on open water than on land, although the number of examples is so statistically insignificant that it's hard to make any confident conclusion as to the odds, and mooring in an area protected by taller objects limits your exposure.
4.) Lightning is big and bad--and if it chooses to strike a boat with "lightning protection"-- it won't know the difference.
In light of those facts, I'll move forward with the tent system, try to avoid the biggest downpours, and trust my odds if they come.
John wrote:
Never in over 40 years in and around small open boats, and nowhere in my vast library of small boat magazines and books, have I ever heard of a SINGLE case of lightning striking a small boat while in use on the water. Not once. Neither in open water nor close ashore.
OF COURSE it could happen, but I think the odds are similar to being struck by lightning while undertaking ANY sort of outdoor activity. Which aren't zero but are very low.
However, he doesn't take any chances with his customers. I've been to at least 2 Okoumefests where a rumble of thunder caused him to order the entire fleet out of the water until he was sure that the possibility of lightning was gone. Good to know that someone is looking out for us while we're in the throes of a boating frenzy.
Laszlo
Along the lines of electrical safety, Johns post mentioning the concept that there are no insulators, just conductors of varying resistance, that is EXACTLY right.
Air conducts electricity at about the rate of 20k volts/inch in "standard" conditions.
Remembering that ANYTHING can conduct electricity sort of keeps you in the right mindset. I got nailed a couple times by the fly back in old TV sets. Didn't even touch any wires, merely came close enough. Fortunately not enough amperage behind it, and I wasn't providing ideal conditions to get the full effect, to get hurt, but it still smarted right good!
Proper lightning protection really does work though, but think of it like a dog for protection. The point isn't to get a dog to eat the bad guy, but so the bad guy goes somewhere there simply isn't a dog... It helps to prevent ideal lightning strike conditions. A very passive "soft kill" if you will. A boat with a tall metal mast that is isolated from ground, well, you're starting to ask for it, like a radio antenna. Amateur radio enthusiasts are frequently pretty well versed. Wood boat, wood mast, non metal rigging, not a ton of surplus electrons hanging in those conditions.
Mike
Lake Perry, Kansas - big midwestern thunderstorm, about 100 boats moored at the yacht club, mostly standard firberglass sloops of 20-40 feet. Most folks retreated to the clubhouse, etc. as storm passed. Lightning struck a sloop and blew the grounding plate that was fiberglassed into the hull (per boat original construction design) right out of the bottom of the boat. Folks at the club realized the close stike must have hit one of the boats and went to look around the docks as the storm passed. It soon became evident the boat that was sinking was the unlucky winner. Some quick damage control efforts by many hands kept the boat above water.
Ontario, Canada, many years ago as a kid. Summer storm while fishing walley from an aluminum canoe, quite close to 30-50 ft high "rock dome" type of island. Lighting stuck an isolated pine on the island, burnt up the tree, but rain helped put out that fire. Pretty much felt like having the wind knocked out of us, and hard to hear for a while afterwards. The fish kept right on biting!