Everything looks right at Mare Oyster Bar. Patrons are shoulder to shoulder at the bar and knee to knee at the tables, which are only a slender leg’s worth of space apart. The lighting is just low enough, and the floor-to-ceiling windows that stand in for walls are open to the breeze. It’s a fine night in the North End. Shellfish line a bed of gleaming ice, on tantalizing display. Chic women teeter past on their way to the restroom, turning to check out the oysters. They are wearing their shuck-me pumps.

But everything does not work right at Mare Oyster Bar. The table reserved for eight becomes available at 8:30. Orders are taken at 9. It is another half-hour before oysters arrive. Some tables have bread; others never will. There are long stretches between each course. A server may, at long last, apologize for the pace of the meal. But he won’t offer a complimentary appetizer. Or a crust of bread.

Mare Oyster Bar is a remake of restaurateur Frank DePasquale’s Mare Natural Coastal Italian Restaurant. DePasquale also operates Bricco, Umbria Prime, and Splash, among others. In February, he closed the restaurant, renovated (Mare’s ugly LED lighting has been replaced by mirrors and televisions), ditched the unwieldy name, and added a new focus: oysters. Considering the success of Neptune Oyster in the same neighborhood, this was not at all a bad idea.

And the oysters are beautiful, sparklingly fresh, correctly shucked, swimming in their liquor without shell shards or grit. They are served simply, with lemon wedges, mignonette, ketchup, and horseradish. With one or two exceptions, the rotating selection draws from New England: briny Wellfleets, metallic Belons and plump Bagaduces from Maine, and more.