Saltwater help?

Sister-in-law kept the boat after a divorce with electronics but no tackle. I plan to go down for the Destin Rodeo in Oct but really need some good advice. What is the best method to protect my freshwater gear against the salt, should I buy new or pawn-shop gear for a single trip? I'll leave the rods/reels with her as I am a Missouri resident and use a jet or pontoon to fish here and the tackle won't be usable for crappie and bass! Any other tips would be greatly appreciated too! Thanks.........Shoalrunner