Correct. The lightning rod is a spike of some conducting metal poking up into the air, with a strap or cable of wire leading to a copper plate in contact with the water or (in the case of an old square rigger) the copper anti-worm hull cladding). This supposedly leads the charge directly to ground without it having to heat up and possibly damage a wet wooden mast or other high-resistance part of the ship.

In modern yachts without lightning protection, a jury rig rod could be deployed by clipping a pair of jumper cables to the stays (steel cables supporting he mast) and throwing the other ends of the jumper in the water. Supposedly, this will cause lightning to hit the aluminum mast, travel down the stainless steel stay to the copper cable, and from there safely to the water.

But this is not recommended. I suspect at least part of the charge will go through the mast straight down into the boat, and go to ground by punching a hole in the hull, instead. In any case, even if the boat survives undamaged, you can kiss all your fancy electronics goodbye.

Even in Florida, where we get thunderstorms almost every day in the summer, it is very rare to hear of a boat getting hit by lightning. But when they do, there is almost always some damage, usually the electronics, regardless of whether they have lightning protection or not. The common wisdom is that a rod will provide good protection when hit, but will make you more likely to be hit. You pays your money and takes your chances.