Even when your boat sustains a direct hit by lightning, it's unlikely anybody on board will get hurt, according to research done by Chuck Fort, an associate editor at a newsletter put out by BoatU.S. Marine Insurance.
After reviewing 998 lightning-related claims submitted to the insurance company in the past five years, Fort found that nobody had died and only "a handful" of people had been seriously hurt when lightning damaged their boats.
"The people who are injured are in open boats - runabouts and bass boats," Fort said. "Those guys are out there fishing. If they happen to be the tallest thing out there they can get hit or their rod is hit."
Fort found that the company has only seen two lightning-related fatalities since it has been keeping records - neither occurred in the past five years. However, in the cases where boaters were hurt, the wounds were serious. Lightning caused "burns in their shoes and they got injured pretty badly," Fort said.
The research was done for a story in the current issue of Seaworthy, a quarterly publication put out by the insurance company. BoatU.S. Marine Insurance, Fort said, is one of the largest watercraft insurers in the country.
Fort's research also revealed that no type of boat is immune to lightning strikes.
"Even Jet Skis were hit," he said. "Two or three were hit even while people were on them."
Turning off electronics will not protect them from damage in a lightning storm, Fort said.
"At least some - if not most - of the damage is not caused by the lightning itself," he said. "It's caused by an electromagnetic cloud" that accompanies the lightning.
And unplugging electronics can inadvertently worsen the damage that a boat takes from a lightning strike. In some cases, Fort found that when lightning hit a mast on a sailboat, the current would travel down the cables. When the cables were unplugged, the current leapt through the air and would look for another path to the water. In one case, Fort said, the current left a loose cable and blew a 3-inch hole through the hull.
When sailboats were hit by lightning they were most often stuck in the mast. But, anecdotally at least, the type of material the mast was made of made significant difference as to how it withstood the strike.
Aluminum masts rarely were damaged when hit, Fort said. Carbon-fiber masts, which are favored by high performance racing yachts, did not hold up. Wooden masts were the worst.
"In one claim, a wooden mast that was partially rotted was destroyed when the charge heated up the damp mast, causing the moisture to suddenly expand [witnesses said it `exploded.']," Fort wrote in the Seaworthy article.
Fort said he was surprised to find that the Chesapeake Bay had the second-highest rate of lightning strikes in the country, but it is difficult to interpret these findings since his research looked only at claims submitted to BoatU.S. Marine Insurance. The statistic could indicate that BoatU.S. Marine Insurance is used more by more boaters here than in other areas of the country.