Commercial shipping fleet and its emissions can be modeled in detail, but the emission from leisure craft are often invisible for activity based, bottom-up emission inventories. A new model (FMI-BEAM) describes the emissions from the leisure craft fleet in the Baltic Sea area, complementing the existing STEAM emission modeling suite. BEAM combines information from over 3000 boat marina locations, national small boat registries, Automatic Identification System data and boat survey results to derive leisure boat emissions for over 250,000 boats around the Baltic Sea coastline. The location of marinas and boat counts were determined from satellite images and other available data. With the BEAM leisure craft simulation model the spatial and temporal distribution of air emissions can be estimated. The presented results describe our first attempt to generate fuel consumption and emission inventory for small boats which have been underrepresented in current emission inventories. Small boat activity often occurs near the coastline in vicinity of populated areas and leisure craft emissions contribute to local air quality. The emissions of carbon monoxide and hydrocarbons are high compared to the emissions of commercial shipping, because very high emission levels are allowed for old small boat engines according to current legislation. The approach described in this paper can be applied in larger scale, for example to cover European coastlines in the future.