Explanation of Two-Stroke Vessel Engine Regulations and Restrictions

Boaters are concerned because their vessel repair shop, mechanic, or marine store has told them that soon they will no longer be able to legally use their vessel on California waterways.

The fact is, there is no statewide prohibition on the use of high emission two-stroke vessel engines statewide and there is no plan to prohibit them.

The state regulations, from the California Air Resources Board (ARB) Recreational Marine Engine Program, are concerned with the manufacture and sale of NEW marine gasoline two-stroke engines. ("New" means the engine has never been sold to an end-user.) The ARB regulations ordered vessel engine manufacturers to build cleaner emission engines meeting increasingly strict standards with steps in 2001, 2004, and 2008. These ARB regulations do not affect the use of any vessels on waterways, other than the fact that consumers will obtain improved gas mileage from the new models now on the market.

A small number of cities, counties or districts have adopted ordinances on drinking water reservoirs that restrict or ban the use of high emission, carbureted or electronic fuel injection (EFI) two-stroke marine engines.

To date, there are only 11 lakes with use conditions for high emission vessel engines, mostly in northern California. There are no salt-water or river restrictions based solely on high emission vessel engines.

Cleaner technology direct-injection two-stroke marine engines, manufactured since 1999, can be used on all waterways in California, except for some waterways that have generic prohibitions, such as banning all motorboats or all personal watercraft.

For more information, and a list of bans and restrictions, please visit, and direct your customers to, the Division of Boating and Waterways' Website on this topic: http://www.dbw.ca.gov/Environmental/TwoStroke/.

We hope this clears up any confusion about this subject. Should you have any questions, please contact DBW at (888) 326-2822.