The use of SCR technology and DPF technology in the maritime industry allows the reduction of toxic substances into the atmosphere. SCR systems also meet the new regulations of the International Maritime Organization IMO, which introduced the Tier III standard for special zones (ECA) such as the Baltic Sea, the Mediterranean Sea and the coast of the United States where all ships built after january 1st 2016th  need to reduce nitrogen oxides (NOx). Ships that decide to operate all over the world must therefore obtain systems enabling entry into ECA zones. DPF filters, on the other hand, are installed on units operating in coastal zones where, due to the proximity of urban buildings, particular attention is paid to the quality of the air. Vessels such as passenger ferries, supply ships, pushers, dredgers with DPF filters installed, in addition to contributing to the improvement of air quality in many port cities, can count on reductions in port fees.