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Blinding and without warning, dazzling bursts brighter than a welder’s arc caused nearby objects to momentarily disappear from view. Seconds later deafening rumbles and bone-jarring bangs reverberated through the hull. Electricity sizzled in the air. After the initial blasts, rigging shrieked and anchor lines groaned against savage wind. Then came rainfall so torrential the impact of its heavy drops punched craters into the sea’s surface. A thunderstorm’s rage at the end of an idyllic day personified Armageddon, reminiscent of childhood summers in southwestern Ontario. Earlier that day menacing clouds prompted me to seek sanctuary. James Bay on Prevost Island still had room to anchor, albeit exposed to blustery winds down Trincomali Channel. As evening dimmed, the distant storm expanded and intensified. The blackened sky blazed with sheets of lightning. Rampaging forked lightning occasionally struck the water, splitting to run along its surface. The thunderstorm was clearly headed straight toward us, like a creeping artillery barrage. Thunderstorms seldom detonate over Victoria, but that might change with warmer summer temperatures according to Environment Canada. Victoria averages only three days per year with thunderstorms, in contrast to Vancouver’s six, and southwestern Ontario’s 30. But, we’re seeing a few more in the forecast. When daytime temperatures reach 80 degrees Fahrenheit the chance of thunderstorms forming is greater. Compared to southern USA we aren’t even in the high-voltage game. There, typical seasons endure thousands of thunderstorms and millions of lightning strikes. Globally, over 50 lightning strikes occur each second. More science and debate on theories of lightning, and protection from it, exist than will fit in this short article. However, essentially, when big, fluffy cumulus clouds, created by rising moist air, evolve into dark anvil-shaped cumulonimbus clouds, lightning may not be far behind. A negative electrical charge grows at the cloud’s underside, while a positive charge develops in things on the ground. It’s the connection between the two charges that is the visible lightning, which may travel up and down. Since the earth-bound charge is attracted to the cloud-borne charge, it’s usually found on the tallest point. A quick glance around your deck will easily identify your boat’s pinnacle – and it could be you. Being a fatalist - easy to be when there’s no place to hide - I hunkered down in the cockpit while the tempest swept our anchorage, intending to get photos of Thor’s tantrum before being blasted into another space-time continuum. Hairs on the back of my neck - and elsewhere - tingled from the supercharged saturated air. Lightning struck through the bay, barely the length of an insurance adjuster away from the boats moored in it. About insurance, what happens if Thor scores a direct hit? Most Canadian pleasure boat coverage includes lightning damage, but you should check your own policy. Local underwriters say that lightning claims are rare, in stark contrast to vessels in Florida. Estimates are that some 20% of sailboats there are struck annually. Contrary to popular cliché, lightning can strike twice. Reportedly, the record number of strikes to one boat is five, and, the highest repetition rate is twice in ten seconds. Most lightning strikes - the diameter of a 25-cent coin - deliver 100 million volts at temperatures reaching 36,000 degrees Fahrenheit. Danger exists within ten miles of a storm, but strikes can happen 20 miles out. To estimate your distance to a storm, time the interval between lightning flash and thunderclap - five seconds equal roughly one mile. To ignore the likelihood of being vaporized, I kept busy with my camera until driven inside by painful rain. Only lightning flashes illuminated many shots, producing ghostly, shaky images of the bay and neighboring boats. Periodically the electrifying glare revealed wide-eyed boaters peering from their craft - who should have been comforted seeing Ceilidh’s mast standing tall above their crouching superstructures. A boat zapped by lightning can be seriously damaged, risk explosion, lose critical equipment, and see its crew burned or killed. Since people are better electrical conductors than air (due to body’s water content), crew members can become lightning rods. This happens when the lightning’s charge leaves one conductor for a better one, which it always seeks. Even boats with lightning protection systems - few have them - are vulnerable. There is no way to lightning-proof a boat, only ways to encourage the energy to pass through more easily, with less damage. Some boaters just fasten a length of chain to their rigging and drag the other end in the water, but it’s very important that all equipment is properly grounded. Safety precautions abound besides seeking shelter ashore. Common sense is the basis of most, including: stay belowdecks, low near the centre; disconnect electronics, lower antenna; avoid connection between you and metal or water; don’t use cell phones; avoid contact with anything bonded to a lightning protection system; keep away from masts; and if struck, check thru-hull fittings to ensure they’re intact. What a show! The tempest pummelled our bay for only a half-hour, but each furious moment seemed a lifetime. When the wind later subsided it was difficult to believe such frenzy had visited. No boats in our bay were harmed in the making of our high-anxiety thriller. Although that storm occurred some seasons ago, the sound of distant rumbling still causes me to scan the anchorage, hoping that mine isn’t the tallest mast. Eric W. Manchester is a Victoria based writer, photographer & single-handed sailor. www.ewmanchester.bravehost.com ...back to 48° North title page.
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