I bought fuel in about 7 countries last year. USA, CA, Mexico, Panama, Berumda, Horta Port., Spain. I guess my experice is different then the others... In 2004 I found several places that only take cash. For example In Acapulco Mexico Local currency. No travelers checks. No exceptions. I have had to order fuel 3 days in advance. (actually they said 1-2 days, but is was three) This was for only 1,300 gallons of fuel. Oh the sailboaters were not happy because we shut the fuel dock down for three hours and then they were out of fuel when we were done... One really complained at us, they left and a day later we were in 50 knot winds, sea state sucked, and their rigging failed, we were the closest boat. They made landfall sucessfully, but we were their backup plan. Never insult another boat they might be the only one available to come to your aid! I also found if you ask, you can get a 5-15 cent gallon discount for cash, since I usually buy at least thousand gallons I try to get the discount. In bigger ports I used bunkering agents... Panama and on the NAR. But in a lot of places that are small, bunkering agents were not of much help. If only one place sells fuel then there is not much benefit. I always start with something like "whats the price for the fuel" Then I say thats too bad, I guess I only need my minumin fuel amount, I then say that I would have bought enough to fill my tanks if the prices is x-0.30 a gallon. This works about 50% of the time.