The seafood night markets clustered around Beihai's waterfront district are the main reason to be here after dark. Vendors grill, steam, and stir-fry fish, crab, prawns, and shellfish to order at open-air stalls, and the smell of charcoal and garlic from three streets away functions as reliable advertising. The Gulf of Tonkin produces a particular variety of crab and several species of shellfish not found further up the Chinese coast, and the Beihai preparation — heavy on garlic, ginger, and Guangxi spice paste rather than the more restrained Cantonese approach — suits the ingredients.
Come with a group large enough to order broadly, point at whatever looks most active in the display tanks, and eat at the plastic tables regardless of the tablecloth situation. The beers are cold and cheap. This is not where you go to be impressed by service or décor; it is where you go to eat very good seafood in very large quantities for a very low price while the subtropical night air comes off the Gulf.