Yummy is the most-recommended of the cluster of family-run Vietnamese seafood places in the back streets one block in from the seafront. The format is unfussy: pick from a board of fresh fish, prawns, squid, and clams, choose a preparation, and the kitchen sends it out at street-stall prices. Hot pot for two is excellent value and a proper meal for the price of a beer in Hanoi.
The owners speak English well, the kitchen is visible from the dining room, and the bia hoi (fresh draft beer) is poured by the litre. The restaurant fills early; come for an early dinner or be prepared to share a table.