Motorboats need fuel and that is getting more expensive. A few simple measures can help to reduce fuel consumption in order to save money and the environment.
For years boat manufacturers have tried to make their products faster so they can sell better. But with fuel prices of $ 1.50 or more per liter, it’s time to rethink and focus more on efficiency. If, with optimized driving, less than a mile per liter of gasoline jumps out, this shrinks again significantly at full throttle, which is why the most important measure can only be: Gas off. But that is by no means the only solution.
If you go fishing for 20, 40 or even 60 miles in the morning and put the lever on the table, you are not doing anything good to your wallet or the engine. The time saved in this way is reflected in the disproportionately higher fuel consumption (and pollutant emissions, ed.). It is better to find the so-called sweet spot, i.e. the speed range in which the engine provides the best performance with the lowest fuel consumption. This is partly a matter of feeling, but there are also parameters that can be used as a guide.
On a large number of boats, the ideal speed is between around 25 and 30 knots. Diesel engines will hit this sweet spot somewhere beyond 1800 RPM, while gasoline outboards are usually most comfortable between 3000 and 4000 RPM. This varies from person to person and depends on factors such as displacement, hull design, engine power, propeller, dead-up or trim.
Modern machines have electronic control modules that supply the cylinders with the smallest amount of fuel required for the required power. In addition, there are often digital measuring instruments that help to monitor the gasoline flow, such as the SmartCraft system from Mercury with the Eco Feature software, which automatically calculates the sweet spot of the boat. Yamaha also offers digital fuel monitoring systems that are well worth the investment if they are not already installed as standard.
Other electronic aids such as Navigation software can also be useful in saving fuel. At least for motor boats, the old geometric truth applies: the shortest connection between two points is a straight line. Small course deviations of a few degrees can add several miles over longer distances and that quickly turns into money. Calculating the shortest route on the plotter can save hundreds, maybe even thousands of euros (and reduce emissions, ed.).
Horsepower and propellers
A truism is that smaller engines save gas, but that’s only true to a certain extent because an underpowered boat is extremely inefficient. Smaller engines have to be run at higher speeds in order to achieve the same performance, which in turn increases fuel consumption, which then nullifies all theoretically calculated savings.
Whichever engine you choose, the propeller is of paramount importance to getting the best out of your boat. With the right screw, the boat will run in the engine manufacturer’s recommended speed range, with a full tank, complete equipment and the entire crew. The wrong propeller selection means that the engine is running either too low or too high a speed, which in turn has a negative impact on fuel consumption. In short: If the performance is not right and the fuel consumption is above the pain threshold, it may be due to an unsuitable propeller.
Vegetation looks like a block
Aside from having the best engine performance, a clean underwater hull is a simple and effective way to save fuel. Mussels and other vegetation increase friction, which means you are slower to travel and also use more fuel. It works best on a clean GRP hull. Wax may feel smooth, but it keeps the air bubbles close to the surface of the trunk, which increases friction. Underwater paint is less rapid than the bare hull, but still better than vegetation around house corners.
Another tip for more efficient driving: Have your boat removed. What is not needed on board should stay on land. Packing discipline, a clean bilge and empty bait tanks (when not fishing) help.