I would count my blessings if I could find a way to stop this (We even have these thunder bumpers up here in the North West but nothing compared to you guys down in the deep south. I spent four years in Texas and I can vouch for how ferocious the southern storms are. I have to laugh at the Portlanders and Seattleites who panic at the sight of a baby thunder bumper. After trying to protect first my San Juan and now the Ericson I came to the conclusion that the best protection possible is to dance around the boat uttering an enchantment of protection. I believe that suggestion came from Christian.
With a lightening bolt, you are dealing with millions of volts and you cannot provide a large enough ground to dissipate the field. You listen to reports of fully "protected" boats getting hit and the flash travelling down the forestay then arcing to the mast and again to the stove before dissipating while the owners are sitting on the settee are terrifying!
The best thing is to get off the boat if possible. If not sit inside in a spot that is not near anything metallic and cover your ears.