The C18 ACERT marine propulsion engine has commercial application ratings of 460-725 mhp (454-873 bhp) at 1800-2200 rpm that meet IMO II emissions regulations. with the IMO II only engine ratings, Caterpillar offers the new added reliability benefits of the improved cooling system for international customers. In addition to the benefits the C18 ACERT’s advanced marine engine technology brings, you welcome aboard legendary Cat support. No matter where your spirit of adventure takes you, rest assured that there’s a Cat dealer or one of our authorized marine dealers close at hand.