Boats and bolts: protecting you and your vessel from lightning

Capt. Kirk is on leave for a while. In the meantime, enjoy a version of this classic from our archives.

With the storms of summer sure to come and locals having more free time to go out in their boats, there is one element of danger you need to consider: lightning.

Many people think that if you’re not right under the storm cloud, you’re safe. Not true. Lightning can strike up to 20 miles away from what’s known as a cumulonimbus or thunderhead cloud.

There are several stages of development to watch for here in Southwest Florida, especially while out on the water. Building puffy white clouds are cumulus clouds. They are the type that Care Bears live in and Skittles fall from. Just kidding.

Cumulus clouds signal the first stage of a developing thunderstorm. All atmospheric conditions are caused by heat exchange. We all know that heat rises. As the Earth is warmed by the sun, patches or columns of warm air rise. Thermals are created as the spiraling air rises. Above every thermal is a cloud. In summer, these thermals can rise very quickly, and as cumulus clouds grow, they reach the cooler upper atmosphere.

We have all noticed water droplets forming on the outside of a cold beverage in a glass. This is what happens in the cloud.

With the friction of the rising hot air and the descending cold-water droplets, electricity — lightning — occurs.

This path of electricity sometimes reaches ground objects as the earth and atmosphere molecules collide. This is the second stage of a thunderstorm, known as the mature stage. It’s also the most dangerous because strong downdrafts are produced as cold air flows downward and hits the Earth’s surface.

If you are out on a boat, it is wise to be watching for these developing storm clouds and head to safe harbor.

The third and final stage of a thunderstorm is the dissipation stage. The energy has been spent. Except for a few rumbles of thunder, the wind and rain have let up. This occurs mainly in the evening, as the sun is lower and the heat exchange is less intense.

Experienced boaters will wait out a storm and head home when the seas are flat after this stage of the storm. It might mean being out after sunset, but it is safer.

Sailboats are known to attract more lightning strikes than powerboats. Sport fishing boats, however, sometimes have long aluminum poles called outriggers, which are used to spread the bait when trolling offshore.

People who own this sort of vessel — sail and power — have their rigging grounded. This means that the tall metal structure is bonded by heavy gauge wire to a grounding plate on the bottom of the boat. In sailboats, it’s usually in the heel. The idea is to dissipate the electrical charge through the grounding plate in the event lightning strikes, intended to create a path away from passengers.

I have been on a sailboat that was struck by lightning. The charge blew out all our electronics but did no damage to the vessel itself. We were on our way back from the Dry Tortugas, so we made our way back, navigating by pilotage and dead reckoning to plot course and speed.

Lightning is nothing to ignore, especially here in Florida, the lightning capital of the world. A good rule of thumb is: If you hear thunder, you are in range of lightning.

It’s also when you should apply these rules for safety:

• Get inside a safe building.

• Do not hide under a tree.

• If out in a small boat, you should have already been docked or beached someplace safe to wait out the heaviest part of the storm.

• Don’t fall victim to “get-there-it-is” — wanting to reach a destination even when conditions are dangerous — persuade you into trying to get home before the storm hits. If you have a cabin on your boat, drop an anchor in a protected cove or bay and wait it out. A storm that lasts only about a half hour might feel like several hours, but it is safer than being on deck.

By all means, enjoy our great outdoors — but do it safely. You can’t enjoy anything if you let Mother Nature turn you into a crispy critter.

Fair winds; calm seas. ¦

— Capt. Dennis Kirk and his wife, Nancy, are avid mariners and outdoor enthusiasts. Since the 1970s, their love of nature in Southwest Florida has allowed them to experience the dream of writing about their travels and adventures of sailing, fishing or flying out of their homeport on the Peace River, the old DeSoto marina.

The post Boats and bolts: protecting you and your vessel from lightning first appeared on Charlotte County Florida Weekly .