This report presents information on the environmental impact of vessels during their general operation. It is shown that the emissions from vessels can substantially contribute to local air quality problems over land and also impact the climate change process. Up to now, the contribution of the maritime sector to air quality problems in Latin American and Caribbean coastal cities has received little or no attention. Studies for the United States and Europe show that the contribution of this sector may however be significant. Given the persistence of air quality problems in Latin America, it appears worthwhile to consider this sector in emission inventories and mitigation policies.The recommendations at the end of the report include several measures that may be implemented at little or no costs, but that do provide incentives to improve the environmental performance of the sector. Based on further research on the particular contribution of the shipping sector to air quality problems, more far reaching measures may have to be considered. With respect to climate change, it is recommended to stimulate participation in trials with the IMO CO2 index that is under development.