Disappointing. We approached the marina a few minutes before 1800 and the dockmaster told us over the radio that his office and the fuel dock was closing at 1800, but that we could do self service fueling with $100 limit each time but able to enter credit card multiple times. We needed 300 gallons and each $100 got us about 17.5 gallons. Pretty soon our first credit card stopped working with a fraud alert and we switched to Amex which kept working. Over the radio, the dockmaster also told us we could use a slip # in concourse D or E, but we didn't hear the actually numbers for these slips. We found an empty slip in E and fortunately no one showed up to claim it. Of course, no one was available on the dock to help with lines at this time.