This paper highlights two different fishers’ knowledge systems in the Philippines. These fishers’ knowledge systems underlie distinct strategies for sustaining a continued livelihood from the sea. They encompass paradigms for success in fishing and are oriented to contend with change and uncertainty. They incorporate ideas about closing or opening resources and sharing or exchanging opportunities with outsiders. What fishers seek to manage are the conditions of making a living, which include moral concerns of equity in relation to scarce opportunities. Not all resources are well known and some are highly enigmatic. Fishers’ relations with resources are linked to the current economic and social values of fish within both market and community economies.