The increasing oil prices and the minimal pricing on catch are making energy optimization a topic of current interest for the bottom trawling industry. Experiments with different trawl configurations in order to optimize the gear are both costly and time consuming. The consequence is that in order to ensure the highest possible catch rate, the skipper chooses to use heavier and more rugged components than what is optimal, increasing the tow resistance and the environmental impact. Fishermen claim that the y want to know more about the consequences with respect to efficiency after altering gear configurations. In order to provide more knowledge about this, i.e. through computer-based decision support, this project focuses on the scientific challenges identi fied as regards gear optimization. These are to design tools based on efficient mathematical methods for calculation of dynamic behavior of trawl systems, to extend the understanding of hydrodynamic loads on net structures and trawl doors and to investiga te the reaction forces between the gear and the seabed. Extensive testing of bottom trawl equipment in model scale, and development of appurtenant mathematical models will be central in the project. Findings in the project are potentially very important f or the fuel consumption and environmental impact of future bottom trawling, making this fishery more profitable and environmentally sound. For the manufacturers of bottom trawl gear participating in the project, the findings will contribute to further opt imized design and thereby potentially higher market shares.