New regulations require ships operating in certain waters to meet new emission standards. These waters include most regions where shipping passes through at some point so that up to 90% of ships are affected by the new regulations. Since marine engines typically burn lower grade and higher sulfur fuels than land-based diesel engines, there is a need to remove sulfur and other pollutants from the exhaust gases. Retrofits on ships to now add environmental equipment are in progress. As this is a new application there are new challenges, including finding a footprint on the ship for the equipment as well as proper material selection for scrubbing diesel gases with seawater or recirculated scrubbing water. While this is a new application, there are many lessons that can be learned from scrubbers used for coal-fired boilers and incinerators that have been in use for many years. This paper reviews the conditions and requirements of these new marine scrubber systems and in particular focuses on materials of construction to control corrosion to manageable levels.