This paper highlights the significance of securing tenure over ancestral waters for indigenous peoples. It narrates the initiative of the Calamian Tagbanwa tribe of Northern Palawan to map their ancestral domain to secure their tenure and assert their resource rights. It also identifies challenges presently faced by the Calamian Tagbanwa in managing their ancestral waters, including governance complications brought about by overlapping provisions in the Fisheries Code and the Indigenous Peoples’ Rights Act. The Ancestral Lands and Waters of the Indigenous Tagbanwa Communities of Northern Palawan was prepared by PAFID for the project “Mainstreaming Voluntary Guidelines on Governance of Tenure,” implemented by ANGOC and supported by the Food and Agriculture Organization (FAO) of the United Nations. PAFID and ANGOC express our thanks to members of various indigenous communities, local government units and line agencies that contributed to the preparation of this study. The views and information provided in this document do not necessarily reflect the views and policies of FAO.