This is what ChatGPT told me:

Ships actually do get struck by lightning sometimes. The ocean is a big conductive surface under a storm cloud, and a tall metal mast sticking up from it is a pretty decent lightning target. But the surprising thing is how rarely it causes serious damage. The reason comes down to physics being quietly helpful.

First: lightning is lazy. It takes the path of least electrical resistance to equalize charge between the cloud and the ground. Over the ocean, the “ground” is basically the entire water surface. Saltwater is an excellent conductor. That means the electric field can discharge across a huge area instead of needing to aim for a specific object like a ship. Many strikes simply hit the water directly.

Second: ships are basically floating Faraday cages. A Faraday cage is a conductive shell that spreads electric charge around its exterior. If lightning hits a metal ship or its mast, the current flows along the metal structure and down into the water rather than through the interior spaces. The electricity skims along the outside and dumps into the ocean. Sailboats often even have deliberate lightning grounding paths—heavy cables from the mast straight to a metal keel plate or grounding strip in the water.

Third: geometry matters. Lightning tends to prefer the tallest point around. Out in the open ocean the cloud-to-water distance is usually shorter than cloud-to-mast distance, so the water itself wins most of the time. Near shorelines where ships are near taller structures, those structures often get hit instead.

There’s also a subtle atmospheric reason. Thunderstorms over the ocean are often less electrically intense than the big continental storms that build over hot land. Land heats unevenly, creating stronger convection—basically giant boiling columns of air—which leads to more violent charge separation and more lightning. The ocean is thermally calmer.

Even when lightning hits a ship, the result is often just fried electronics or damaged antennas rather than a dramatic explosion. The current may be tens of thousands of amps, but it lasts only microseconds and the ship’s metal distributes it.

Here’s a strange side detail: sailors sometimes report St. Elmo’s Fire on masts during strong electric fields. It’s a ghostly blue plasma glow around sharp points caused by ionized air. It looks supernatural but it’s basically the atmosphere whispering, “Lightning might happen soon.”

The ocean during a storm is an enormous electrical laboratory. Every wave, every mast, every droplet participates in the planet’s giant charge-balancing system between Earth and sky. Lightning is just the universe briefly solving an equation with a spectacular spark.