The Marine Unit maintains a fleet of 8 boats. Their primary patrol (and firefighting) boat, on Lake Washington, is a 36 foot aluminum custom built boat with twin 200 horsepower engines. When it was time to replace the original outboard engines on this boat, which was purchased in 1985, the Marine Unit replaced the noisy and polluting two-stroke engines with more efficient four-stroke engines. The new engines are much quieter and more dependable. As a bonus, they are more fuel efficient, which has the benefits of lower costs and less environmental damage. Even though the Marine Unit does not maintain a huge fleet, it proudly joins a growing number of King County agencies that are taking a leadership role in environmental stewardship. The Unit will continue to specify efficient engines as the old ones need to be replaced.

The U.S. Environmental Protection Agency has issued regulations requiring manufacturers of outboard marine engines to reduce hydrocarbon emissions 75% by the 2006 Model Year, causing the old smoky, noisy outboard motors to soon be a thing of the past. This means that new and tougher federal emission standards will require engine manufacturers to replace carbureted two stroke outboards and personal watercraft with cleaner, new-technology engines, by the year 2006.

Two-stroke engines have two important advantages over four-stroke engines: They are simpler and lighter, and they produce about twice as much power per pound of engine weight. But, there are four main reasons why cars and trucks (and now some marine equipment) use four-stroke engines:

These disadvantages mean that two-stroke engines are used only in applications where the motor is not used very often and a high power-to-weight ratio is important.

Meanwhile, manufacturers have been working to shrink and lighten four-stroke engines, and that research is coming to market in a variety of new marine and lawn-care products.