Actually Cal thats not quite true, yes maintaining the engine a tuned condition does keep emissions down but not to the level of a newer car with a catalytic convertor. Boats could be much better, and as always the bigger the boat and engine, the more pollution. See the link and table below:
http://64.233.161.104/search?q=cache...emission&hl=en
From the site:
Table D-4
Engine Emissions, New Engines
------------------------------HC (g/kW-hr) --------NOx (g/kW-hr)
Carbureted ---------------------- 7.8-------------------6.2
Electronically fuel-injected---------4.7 ------------------9.9
Three-way Catalyst, Feedback A/F -1.9 ----------------- 2.0
Fuel injection decreases hydrocarbons but actually increases NOx emissions (smog) without a catalytic converter.
From another site (in Australia no less) written in 2000
http://www.bia.org.au/Press/151100.html
"Industry Claims Pollution Figures on Jet Skis "Ludicrous" The Boating Industry Association of NSW has come out fighting against claims that jet skis and personal watercraft cause as much pollution as driving the average automobile 223,000 kilometres - or Sydney to Perth and back 27 times!
Roy Privett, General Manager of the Association, labelled the claims as "ridiculous" and "bordering on ludicrous".
"I've read some nonsense in my time", Privett said, "but this takes the cake". The claims that personal watercraft and the similar Jet Ski are "pollution machines" came from the Federal Government's Coastcare organization.
A spokesman for the NSW Environmental Protection Association also weighed in with a share of nonsense, claiming, "Jet Skis, along with outboard engines, are responsible for 10 percent of Sydney's air pollution on summer weekends". "No accurate figures suggest such a situation exists", Privett added, "and to suggest that personal watercraft are "remarkably inefficient", as one report claimed, is errant nonsense, as today's two stroke engines with their direct fuel injection systems have reduced submissions substantially".
"In fact, today's two-stroke engines conform to EPA standards through to 2002, and in some cases beyond", he added.
According to Heytrack Australia, distributor of the popular Sea Doo range of personal watercraft, the statistics unveiled by Coastcare cited data from tests done on old technology personal watercraft of eight and ten years ago" ..
From the same article:
Surprisingly, well-known environmentalist and NSW EPA officer, John Dengate, said the authority was "more concerned with pollution form wood fires, diesel engines, and vehicles than it was with boats".
So these people criticizing the PWCs are comparing 15 year old technology to newer car technology ignoring the improvements made over the last 5 years. For me this blows their argument right out of the water, so to speak. Just like the people who claimed to have scientific proof that snowmobiles scare bambi, they think with emotion rather than using their brain trying to find the real story.