If any of you want to take the time, you can google for ATM machine locations around Baltimore's Inner Harbour and prepare a map of your own showing the relative locations of ATMs (with the Otakon map (if they would re-map their link) you could print their's off and use that)
Provident, BB&T, 1st Mariner, Bank of America, Wacovia, M&T.
But as someone pointed out earlier, ATMs are usually depleted well before 5.
the closest Provident ATMs as an example:
Pratt Street Branch (this one is like right across the street from the BCC)
250 W Pratt Street
Baltimore, MD 21