Can one find out what the customs fees will be before sailing? Do you need cash in the local currency? I think Mexico will let you use a credit card if you let them know before the paper work is started. As far as I can tell for Mexico, Have a pass port, fishing license, Q flag. A courtesy flag can be bought at port but handy to have it already? Thanks
No customs fees anywhere unless you want to import
your boat to that country.
For Mexico, about $25 per person for visas, about $10 for API harbor fees if your harbor has a port authority, and around $0.80 per night for anchoring
in most big harbors.
You can get your temporary import permit
there; you may or may not want to get your personal fishing licenses beforehand - about $48 per person per year. And you should have a courtesy flag to fly as soon as you are cleared in. I haven't seen anyone use a Q flag.
You also will need ship's documentation
or state registration
for your boat and a crew list to check in.
Personally I would never use a credit card in Mexico; ATM machines are almost everywhere. You should consider taking some pesos along anyway - it involves an element of respect for the country, pesos are always received, and you will get a much better exchange rate from a bank than from a vendor.