They should be accommodating to this extreme situation and at least offer to allow a reschedule of the charter. It's not like they have a line of customers waiting to charter that same Cat! People remember the way they treat you and move your money elsewhere!
The charter company could have chartered the boat to someone else who didn't have the same travel issue/restriction. So it's not like the charter company doesn't have something to lose. Best to have a nice conversation with the charter company to see if your dates can be deferred to a different date. Legally I think you have no standing. Insurance was available and there is always some sort of insurance that will cover you for just about anything given a premium to match. Obviously it's in the interest of the charter company to be on good terms with all possible customers. So I suspect you can wiggle something that is better than forfeiting your charter fees. Good luck!
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