It was hot and noisy in the cabin of Clearwater, a big reproduction Hudson River Sloop. We were tied to a pier on Iona Island, just downstream of the Hudson River Highlands, with a thunderstorm raging and everyone huddling below. I decided it would be more peaceful on deck, so I put on my foulies and went outside. I was standing next to the tiller when I heard a loud bang. My eyes shot to the top of the mast where I saw a small brown cloud and bits and pieces of antenna flying into the marsh. We had just been hit by lightning. And it was amazing. Not only was I still alive, but the deck was soaking wet and I hadn't felt the slightest tingle.

One might say that I was lucky, but the truth is that luck had nothing to do with it. Clearwater has a grounding system to protect it against lightning. Lightning systems can be simple or complex, depending on the boat, and are a safety feature many boaters can install themselves. The system on Clearwater was simple, but effective. The odds of being hit by lightning are pretty slim, but it's not a bet you want to lose.

THE BEST DEFENSETall objects present a target for lightning. On land, that may be a building. On water, it may be a mast.

Thunderstorms produce lightning when water within the storm cloud– liquid or solid–is set in motion by turbulence of the storm. The friction creates huge quantities of static electricity–as much as 30 million volts–and tall structures such as buildings and towers are the most vulnerable.

That means any boat--and particularly sailboats, with their tall masts–also present a raised object to target. Most boats don't get hit, but it does happen, as it did that night aboard Clearwater.

Your best defense is to find yourself inside a Faraday Cage, an enclosure formed by conductive material named for physicist Michael Faraday. If you're safely tucked inside such a cage, the electrical charge will follow the metal and avoid you. An automobile is one example of a Faraday cage, as is an all-steel boat.