June 23, 1998 Writer: Aaron Hoover
Sources: Ewen Thomson, (352) 392-9753
Ted Crosby, (954) 749-9655
GAINESVILLE, Fla. --- When Fort Lauderdale marine surveyor David Pascoe discusses sailboats with prospective buyers, he can bet they'll never ask about one major issue.
"When I do surveys for people buying boats and I tell them about lightning protection, I get a 1,000-yard stare -- it's like, `What are you talking about?'," he said.
If this summer is like past summers, Florida will lead the nation in the number of days with lightning activity, and lightning strikes will kill several residents. Yet many owners of the state's more than 750,000 registered vessels will leave docks in boats that are either unprotected or poorly protected from strikes, putting themselves in danger and exposing equipment on their boats to damage or destruction, according to a University of Florida lightning expert and marine surveyors in the state.
Ewen Thomson, an associate professor of electrical and computer engineering, and two South Florida surveyors say the problem results partly from sailing enthusiasts' and power boaters' ignorance of, or misconceptions about, lightning.
But it also stems from a lack of codes requiring boat manufacturers to install lightning protection systems, Thomson said.
No one keeps track of how much damage boats sustain from lightning each year, but marine surveyors agree costs likely total millions of dollars. Much of the damage results from ruined navigation, radio and other electronic equipment, said Pascoe, a marine surveyor for 30 years. Damage on boats he surveys typically ranges from $10,000 to $40,000 per boat, he said. Another Fort Lauderdale surveyor, Ted Crosby, said he looks into 10 to 15 lightning claims annually, with one recent claim totaling $43,000 in damage.
Tragedies occur on both sailboats and power boats, but lightning kills or injures more people on open boats because it is more likely to strike crewmembers when there is no mast.
A 14-year-old Hollywood, Fla., boy was killed last year after lightning struck while he was aboard a small open boat on a lake in Marion County, according to news reports. Earlier this decade, two Canadian sailors died from hypothermia in Canada after a lightning strike apparently blew holes in their sailboat's hull and it sank, Thomson said.
Most boaters know little about the dangers of lightning or lightning safeguards, Crosby said. "The boaters themselves for the most part know diddly-squat," he said.
Misconceptions, meanwhile, are not infrequent. For example, some sailing enthusiasts believe "grounding" a boat by running a wire from the mast to a connecting plate in the water increases its chances of being struck by lightning, Thomson said. However, reports from marine surveyors do not support this contention, and grounding the mast is the best way to prevent lightning from sparking around the boat as it seeks a conducting path, Thomson said.
"If you don't ground the mast and lightning strikes the boat, it could kill people, it could sink the boat and it could cause a large amount of damage," Thomson said.
Meanwhile, no federal or state laws require manufacturers to install lightning protection, Thomson said. Crosby estimated half of all powerboats and sailboats on the water are not grounded or are improperly grounded.
The surest way for boaters to avoid lightning is to avoid storms. Barring that, sailors should ground the masts on their boats using a No. 4 gauge copper wire connected to conductors in the water, Thomson said. For saltwater boats, a 1-foot metal plate will suffice, but freshwater boats require as a minimum a long metal strip along the bottom of the hull (freshwater does not conduct electricity as well as saltwater). Sailors should also ground the wire to other metal conductors in the water, such as the prop.
People in open boats, meanwhile, should be especially wary of storms. If boaters cannot avoid them, Thomson suggests mounting a lightning conductor -- for example, a push pole -- to attract lightning strikes. Boaters should be certain the conductor is well-grounded to the water, and they should take care to avoid contact with the conductor or the waterline.
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