• The three manufacturers that dominate the market for two-stroke engines used in large container ships are MAN SE of Germany, Mitsubishi Heavy Industries of Japan, and Wärtsilä of Finland.
• An examination of the 2018 annual report of MAN SE indicated that they were no longer in the two-stroke engine business, as Power Engineering had been sold as of 12/31/2019. The company indicated this by stating that they were no longer including "risks  
• in the two-stroke engine business," in the report.
• By 2026, the global marine diesel engine market is projected to be worth $8.1 billion. However, since the majority of the report is paywalled, it is not clear what is included in this.
• Our initial search indicates the requested data may be difficult to find publicly. However, it is possible we could triangulate an estimate based on publicly available data.
• According to the World Shiping Council, there are about 400 liner services globally, most operating weekly. Unfortunately, that does not give us any details on the actual number of ships.
• According to the California Air Resources Board, most shipping vessels "have a single large two-stroke main engine used for propulsion..."
• In 2017, there were 74,823 general cargo ships and 245,609 container ships.

SUMMARY OF AVAILABLE INFORMATION

• Our initial research found that the data on the number of two-stroke marine engines used commercially is unlikely to be publicly available.
• Additionally, in our initial research, we were not able to check on the availability of a breakdown by those with ECU versus those without.
• However, it is possible that we can estimate the total number based on publicly available information. For example, we found the total number of cargo ships and container ships in the world as of 2017. If we can find data that would allow us to make a reasonable estimate as to what percentage of those ships are used commercially, as well as the percentage that are likely to have a two-stroke engine, an estimate could be provided.