Fuel Economics 101 August 9, 2022

Everyone wants to save gas and operate their boats at the most efficient level. That is especially true when gas is running around $5 a gallon. We’ve all heard the jokes: B.O.A.T. is an acronym for “Bring Out Another Thousand” or boats are a hole in the water into which you throw your money.  Yuck, yuck <rimshot>.

But seriously, fuel economy is important. Not only because you want to get the most bang for your fuel buck, but running boats efficiently will add to their longevity. Meaning it can be years before you need to invest in a new motor, or a new boat.

So today’s lessons, class, are about ways to save money on fuel. We’ve arranged these tips in Easy, Trickier and Call The Mechanic categories.

Easy Things You Can Do To Increase Fuel Economy

Check the props. 

A dinged or damaged propellor blade will reduce your fuel efficiency. Make it a habit to check the prop blades frequently during the season. It’s not that hard to replace a damaged blade.

Clean the bottom. 

Usually done at the beginning or end of the boating season, when the boat is pulled out of the water.  Inspect your hull for algae growth, zebra mussels or anything else that might adhere to the hull, increasing drag and decreasing fuel efficiency.  Your boat’s hull should be inspected and cleaned annually.

Lighten the load. 

It’s not brain surgery: a lighter boat goes faster and burns less fuel. So do a quick inventory of the stuff you have stowed aboard. Have an extra anchor or chains? Do you need all that?  Extra coils of ropes or a bunch of heavy duty wrenches or other tools also add weight. We don’t recommend scrimping with any kind of safety device, but eliminating heavy stuff you don’t need to carry on every boating trip will save gas.

Consider the weight of the liquids you carry on board as well.  Water weighs about 8 pounds a gallon. Do you need that livewell topped up for a picnic cruise? If you’re planning on anchoring overnight and want to have plenty of fresh water aboard for cooking or showers, fine. But again, for a quick day trip out fishing, you probably don’t need to top up those water tanks.

Gasoline weighs about six pounds per gallon. Again, decide if you need to top off the tank to the limit.  Most captains figure they’ll need one-third of a tank to get out to a destination, one-third to get back and one-third in reserve, just in case. Do a little back of the envelope figuring and see if you need to top off the gas tank, or can make do with a half-tank or more. 

Redistribute the passengers. 

Of course, if it’s your mother-in-law, you might want to redistribute her back ashore!  But distributing the weight of your passengers evenly around the boat will keep it in good trim, which is fuel efficient.

Reduce wind drag. 

That bimini top is a God-send when it provides shade against a hot sun (and its UV rays).  But it also acts like a wind-anchor when the boat is motoring. If you can, drop the bimini during operation. It’ll help save gas.

Slow down. 

You don’t need to go WOT (Wide Open Throttle) all the time. Going slower and navigating smartly will save fuel. 

Take Your Buddy’s Boat. 

This assumes you have a buddy. But the point is, if you and your friends enjoy fishing expeditions, take a buddy’s boat every other time out. Sharing the load will mean both boat owners will have reduced fuel costs. 

Slightly trickier things you can do to reduce fuel consumption

Check the fuel filter. 

You should do this every 100 hours anyway. But keeping your fuel lines and filter clean will increase efficiency.

Check the water separator. 

You may not even know you have this filter, which is designed to clean out water condensation in your fuel tank.  Again, have it checked and replaced every 100 hours of engine use.

Install a fuel-flow meter. 

There are all kinds of fuel flowmeters that range from pretty easy to install to better-let-the-mechanics-do-it.  But these meters will tell you your burn rate on using fuel and help you calibrate the most efficient speed.

Call the Mechanics

Annual engine tune-up.   

Whether you have inboard or outboard engines on your boat, it’s always a good idea to get them tuned up and humming once a year. Not only will they then operate as efficiently as possible, but regular service and maintenance will ensure your engines will operate efficiently until it’s time to replace them.

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