Most Canadian Dollar credit cards charge the going US exchange rate on the date of the transaction plus about 2.5%.
So for us, even if we charge things on the ship we have to pay the 2.5% fee on every credit card purchase anyway.
I'm guessing that the same would be true for purchases charged in Euros.
Wow, what bank are you with?? I have used my canadian credit cards tons of times on US$ transactions and have NEVER been charged a transaction fee, just that days rate of exchange. I recently made a credit card purchase on product sent from the UK and was only charged the rate of exchage on the british pound. I have a PC mastercard, AMEX and used to have TD GM visa, I also have a family member with CIBC Visa and no extra charges there either.