Yamaha 2019 WaveRunner GP1800R Owner's/Operator's Manual page 9

General and important labels
these standards have 65% lower emissions
than One Star-Low Emission engines.
Four Stars - Super Ultra Low Emission
The four-star label identifies engines that
meet the Air Resources Board's Sterndrive
and Inboard marine engine 2009 exhaust
emission standards. Personal Watercraft and
Outboard marine engines may also comply
with these standards. Engines meeting these
standards have 90% lower emissions than
One Star-Low Emission engines.
4