Because you are paying good money for the charter, I wouldn't go out in anything bigger than 3-5 with 10-15 knt winds. Even in these conditions, you won't have your sea legs and will basically have to strap yourself to the boat.

The tuna should be around for a few more months. I trolled one just off of Seaside NJ a week before Thanksgiving last year. If I were you, I wouldn't force it and just pick another day.