In parts of Vietnam, the van chai is an old, established institution for managing local fisheries and fishing communities. Its principal objectives are: (i) religious functions; (ii) mutual assistance; (iii) specification of the behaviour, rights and obligations of fisheries stakeholders; (iv) catch disposal; (v) governance of fishing operations; (vi) conflict conciliation; and (vii) sanctions. Although locally varied, everywhere the veneration of deities and ancestors, plus the sacred obligations of mutual assistance, provide the van chai with its moral authority. The term ‘van’ has two meanings. In the central region of Vietnam, it approximates the English term ‘guild’, or an organization of people following the same profession. But for riverine fishers, van means a ‘village’, that is, an administrative unit. In this article, I focus on the guild meaning in the south-central region of Vietnam, where fishing villages were established during the southwards expansion of the ethnic Vietnamese, which began in 1693. The three-level social organization used in the north— province, district and village—was applied in the south-central region. When the economic basis of a new settlement had been established, villagers constructed a shrine for the village’s tutelary genie, ancestral sages and wise elders. Dozens of temples (dinh van) in van chai were established, mostly in the 18th–19th centuries, and shrines became the principal cultural and organizational centre of a village. Although fishing communities in the south-central region are no longer linked with farming, as they are in both the north and south of Vietnam, the ancestors of most fishers in the south-central region were northern farmers who had migrated and then became fishers along the coast. Present-day fishers in this region pay great reverence to their ancestors, with village founders worshipped as tutelary deities. The moral basis of Vietnamese society is anchored in the tradition of “remembering the source from which one drinks water”, an expression of the deep sense of gratitude to the ancestors for their labours and struggles to survive and build a prosperous community. In earlier times, the appeasement of a mysterious, and often hostile, natural environment was also important, and led to a strong belief in the power and salvation of numerous deities. The van chai reflected the traditional folk and professional beliefs of home regions, and resulted in the intensification of mutual respect and assistance within the fishing community