Some US coastal polices will even offer a lower $500 electronics
deductible on newer vessels. I don't know of any offshore
coverage) policies that will do that.
Changing the subject a bit:
Our boat builder
put on a thing called a "Strikeshield" but I can't guarantee you that it works (how do you prove a negative?) However, I've noticed that I get a lot of lightning
claims for catamarans stored ashore. So when we hauled the boat, we buried the anode from the strikeshield cable in the dirt. Don't know if that will help, but worth trying.
I have no affiliation with this product, nor do I vouch for it's efficacy. YMMV.