Even though the odds are in your favor that your boat may never be hit by lightning. Don't take a chance, protect yourself. If you are close to shore when a thunderstorm approaches, get in and off the water immediately even if the fishing is good. You might even consider a lightning tracker app. Lightning Tracker
This is the one I use and was great for baseball practice too. (Image was Photoshoped for illustration) We did get into the whites at Phantom on 4/9/15 before the storm but I added the lightning.
The voltages involved in lightning are so high that even materials that would normally be considered non-conductive become conductors, including the human body. The voltages are so massive that if they start to travel through a boat's structure then meet with high resistance, like a jet ski hull, the current discharge, in its attempt to reach ground, may simply blow a hole in the non-conductive barrier.