The long-term sustainability of fisheries depends on maintaining the appropriate balance of fish and ships (or more precisely the fishing effort of the fleet). It sounds simple, but most of the world’s fisheries are overexploited and in danger of collapse within 40 years. In this poster session I explore the paradox of fisheries management with a small system dynamics model of a harvested fishery inspired by the well-known Fish Banks gaming-simulator. The model represents the interaction of the fish stock, regeneration, ships at sea, investment and harvesting. I illustrate bounded rationality and myopia in fleet investment and the resulting formulations for an endogenous investment policy. Simulations show the tendency of fish catch to grow and then collapse. The model is extended to include regulatory policy whose fundamental purpose is to ensure that scientific information about the state of the fishery influences fleet deployment in such as way as to limit fishing effort. Further simulations examine whether, and under what circumstances, regulation can bring about sustainable and economically viable futures for fisheries.