The development of a fishery ecosystem approach implies the improvement of integrated analyses of fisheries by considering biological as well as socio-economic dimensions, and thus improvement of the data available about the fleet structure, evolution, and activity. Since 2000, Ifremer has been developing a Fisheries Information System (FIS), a multidisciplinary monitoring network allowing an integrated and comprehensive view of fishery systems including biological, technical, environmental, and economic components. The FIS covers all the French fisheries, including the often neglected small-scale fisheries. One of the unique features of the FIS lies in the fleet-monitoring procedure—a comprehensive collection of annual activity calendars designed to characterize the inactivity or activity of the vessels each month of the year and, in the latter case, the métiers practised (use of a gear to target one or several species) and the main fishing areas. This survey covers all the fleets and provides minimum but exhaustive information on the vessels. It is particularly instructive for the small-scale fisheries, where catches and effort data are often incomplete. Furthermore, this exhaustive data allows stratification of the fleet and thus provides the basis for (i) the implementation of sampling schemes to estimate catches, landings, discards, or economic performance of the different fleets and (ii) the development of a fleet-métier matrix, giving the possibility of identifying at any one time the structure of the whole fleet, the métier polyvalence of the vessels, and the allocation of fishing effort on the different fishing resources