The harvesting capacity of the European fishing fleet far exceeds the reproductive potential of the resource base. As a result, most European Union fisheries are both biologically and economically over-exploited. A series of fleet-reduction policies have been introduced in order to bring the harvesting capacity in line with target output levels. However, the existence of unutilised capacity may reduce the effectiveness of these schemes as the remaining vessels may increase their individual capacity utilisation (CU), thus offsetting the effects of fleet reduction. In this paper, the effects of stock abundance, output prices, fuel prices and fleet size on the rate of capacity utilisation are examined for a range of UK fleet segments operating in the English Channel. Estimates of CU are derived using data envelopment analysis. Results indicate that the average beam trawl vessel, using existing physical inputs, could potentially increase its revenue by a further 50%, assuming current fish stock levels and unrestricted access to resources. The average gill net vessel could similarly increase its output by 43%, scallop dredge by 28% and otter trawl by 14%. The results suggest that changes in stock abundance are the main factor affecting CU, with no significant trends being observed for the economic variables.