you need to bring:
- cash to tip the dock hands
- cash to tip the fuel dock guy
- credit card for fuel
- credit card for slip rentals
check to make sure you have the right card. not all cards are accepted at all marinas. you will always have your insurance and CG docs on board, but no one will ask for those.
at most marinas, you will hail them on vhf, and they will direct where to go, even if you have an advance reservation.
make sure you have the appropriate shore power cords, and a water hose. if you have a dockside cable inlet, make sure you bring a cord for that - they don't have them there.
any other maintenance stuff - oils, lubes, filters, etc. it is surprising how unavailable these items are at marinas.
other than that, a coupole beach towels (assuming they have pools), a few bottles of wine, some decent vittles, and your best girl.