Saigon Beach 66 Lockhart Rd., tel. 2529-7823

This tiny place can seat only about 20, so avoid coming here at rush hour unless you don't mind standing in line. The decor, an amalgam of nautical paraphernalia -- cheap plastic fish hung from nets -- folding chairs, and Formica tables, isn't likely to impress. But, the authentic Vietnamese fare and conviviality more than make up for the unprepossessing environs. Soft-shell crab and lemon chicken, washed down with French 33 beer, are always a pleasure. No credit cards. $13