Over the past several years, EPA has worked with the marine industry, U.S. Coast Guard
, California Air Resources Board, Southwest Research Institute, and others, including several marine engine manufacturers on a series of development and test programs for the use of catalytic exhaust aftertreatment on sterndrive/inboard (SD/I) marine engines. These efforts include: Laboratory testing of six catalyst designs on a SD/I engine; In-water testing of boat with catalysts over severe operation (fresh and salt water); Full useful life testing of 4 boats with catalysts in fresh water; and ongoing testing of three boats with catalysts in salt water
Results from this testing suggest that significant emission reductions can be achieved from SD/I engines through the use of catalysts. According to the EPA, the fresh water durability study has shown that these emission reductions can be achieved over the lifetime of the engine. EPAe anticipate that the salt water testing will show similar results.
This year, one of the manufacturers involved in the catalyst test programs, Indmar Marine Engines
, completed their own catalyst development and durability testing program in parallel with the work listed above. Now, Indmar Marine Engines is selling inboard marine engines equipped with catalysts, and have reported excellent emission performance. Indmar Marine Engine plans to promote this clean emission technology, which is capable of reducing smog-forming gases by more than two-thirds and carbon monoxide by more than half. (Source: EPA)