Me and my wife went to London about 2 years ago, and drew some money at an ATM on a Sunday. The machine swallowed our USA issued card for some reason, and tore it up! We were stuck. - No banking services, no attendant at this ATM outside a closed shop,....nothing.
What I learned from this:
Have more than one credit/debit card.
Only use ATM's at banks, with banking personnel on weekdays.
Use only ATM's that allow you to swipe your card ( and not insert it)
Have travelers checks available for an emergency.
Leave some cash on the boat.
We envy you guys!