Well, at the hour you'll be looking, you'll have to try a little harder. If you are on Atlantic Avenue, the main street by the Aquarium, with your back to the Aquarium and the water, turn left and walk on the water side of the street about five or 10 minutes down Atlantic Avenue. A block after passing the Boston Harbor Hotel, you'll come to a trailer out of which James Hook & Co. does its lobster business. (The main building burned down last year; they now operate their retail business out of the trailer.) You'll certainly be able to score some lobsters to bring home, and probably can get a lobster roll for an early lunch.

If you're looking for a snack upon arival, the boulangerie at Sel de la Terre, right across State Street from the Aquarium subway station, is a good place to grab a cup of coffee and a bite.