The boating world remained relatively free of many of the environmental causes until the past few years and now you, the boat owner, are expected to do your part. Not that there haven't always been rules, of course, and the Federal Water Pollution Control Act dates back more than a quarter of a century to 1972. It's just that the enforcers had plenty to handle in the automotive and industrial arenas but, now that those groups are toeing the line, the focus is on boating.

Engine manufacturers are facing EPA mandates for pollution control on marine engines in the near future, and are beavering away to find ways to meet the new standards without giving up either performance or low prices.

But there are a number of ways that you can "green" your engine right now to make the waterways cleaner as well as reduce the cost of operating your boat. Let's take a look at some of them.


Many of the newer engines have electronic fuel injection (EFI) systems that put control of the various adjustments in the hands of a black box called an ECU or engine control unit. These mini-computers sense the engine needs and adjust the ignition and fuel flow to meet them. They sample the fuel, test the air and, when operating properly, reduce emissions considerably as well as giving the boat faster starting and better economy.

But what EFI systems really say to shade-tree mechanics like me, who are used to tinkering with their engines, is "HANDS OFF". Your mechanic will need a sophisticated diagnostic computer to see what's going on in your engine, and the old days of adjusting the carb with a screwdriver are long gone. The best thing you can do with an EFI engine is to get it regularly serviced and tuned, and otherwise leave it alone.

Older engines with carburetors, however, are ripe for you to green. As a starting point, keeping the engine tuned will reduce your exhaust pollutants, not to mention lengthen the engine life and reduce your fuel bill. A carb that is running rich is pumping pure gas into the air and dynamiting your mileage while a lean carb is probably burning your pistons, so make sure the carb is properly tuned. By the way, if you don't clean your air filter and it starts clogging with oil and dust, you're reducing the air flow which leads to a rich mixture even if the carb is perfectly tuned.

Your sparkplugs should be removed regularly, cleaned and gapped to the specifications in your owner's manual. Replace them at the recommended intervals, and don't forget to check the distributor cap, points and rotor at the same time.


Using the right fuel seems straightforward: gas for gas engines, outboard mix for outboards, diesel for diesel. But there's more to it than that, and you can make some mistakes that not only hurt the environment, but your pocketbook as well.

As a starting point, use the right octane. If your owner's manual specifies 92 octane, then buying 100 octane is just throwing away money. Your engine will run perfectly on the less expensive fuel, and the higher octane may even increase the pollution from your exhaust.

For outboards, use the right gas/oil mixture: 25:1, 50:1, or 100:1. Again, your manual will tell you the right ratio, but it's up to you to mix it correctly. Too often, it's just easier to pour an entire 8 ounces can of outboard oil into a fuel tank that requires only 6 ounces, but that extra 2 ounces is going to cause your engine to smoke, and that's just pure pollution.

When you fill your tank, be careful not to spill. The air vent for your gas tank is not intended for use as a fuel level indicator, and many boat owners simply pump gas until some of it splashes out the vent into the water. That's not only tough on the environment, but it can earn you a hefty fine into the thousands of dollars. Leaks

Humans and engines have one thing in common: as they grow older, their joints tend to loosen up. With an engine, however, that leads to oil leaks around the valve cover and oil pan gaskets, and under the transmission. If your bilge pump discharges that oil along with the water, it pumps pollution directly into the waterway and can also bring a pricey ticket from the Coasties, who are now watching with eagle eyes.

At every tune-up, have your mechanic make sure that all leaks are sealed, either with new gaskets or by snugging down the bolts on the old ones. Even if your engine doesn't ooze oil, you may dribble when you're checking the dipstick, so it's a good idea to put a drip pan under your engine to keep the oil out of the bilge and away from your bilge pump. An aluminum baking pan or a plastic paint roller tray liner works great, and can either be cleaned or thrown away when oily.


Many boat owners religiously read the labels on the many marine cleaners offered to make sure that the potion is biodegradable, but they often overlook one basic problem: what they are cleaning may not be biodegradable. For example, if you use a biodegradable cleanser to get rid of the oil in your bilge, it is only holding the oil in suspension. If you pump the mixture overboard, you're still breaking the law because only the cleanser is biodegradable, and not the oil.

If you want a basic test of what you can pump overboard, it's anything you're willing to drink. That pretty much eliminates oil, gasoline, anti-freeze, paint thinner, acetone, and perhaps even that weird Kool-Aid drink the kids enjoy. Anything you wouldn't drink is probably illegal.

The key to greening your engine, whether it's an outboard, a stern drive, or an inboard, is to keep it properly tuned, check regularly for oil leaks (and take care of them promptly), and don't put anything into the waterways that you wouldn't drink.

Your boat will be a lot happier, and so will the world you live in.