Global oceans are experiencing not only increased levels of human exploitation, but also major changes to their physics, chemistry and biology. These alarming changes have prompted calls for new and improved conservation and management tools if the future sustainability of oceanic ecosystems is to be assured. Spatial management, although widely used in coastal and nearshore environments, is one strategy yet to be adequately considered for open ocean systems. Resistance to both investigation and implementation of this management approach stems predominantly from the perception that given the highly dynamic nature of the ocean, adequate protection of both its biological and physical components would require regulation of vast regions. To examine this assertion, a series of reserve networks were modelled using the reserve design tool Marxan for an oceanic region off eastern Australia. Consideration was given to a set of biological, physical and social features. Three distinct management approaches were evaluated; fisheries priority, conservation priority, and equal fisheries-conservation priority. Reserve solution area requirements ranged from 7% to 26% of the focus area, falling within the lower end of the range of areas suggested in the published reports. This analysis suggests that percentage area requirements for oceanic protected areas should not be an impediment to further consideration.