Answer
C-store ATMs charge tourist surcharges—ocean-city-atm-cash and banks-atms suggest larger withdrawals at your bank or grocery cash-back instead of three separate three-dollar fees on Boardwalk nights.
Sources: Visit Ocean City · Town of Ocean City
Editorial visitor guidance for Ocean City, Maryland. Confirm current Town of Ocean City, Maryland DNR, NPS Assateague, and NWS rules when regulations or safety apply.
