Despite the boom in electric motors, we are still quite dependent on internal combustion engines, especially when it comes to planing cruisers, trawlers and heavy-duty operating conditions, so fuel economy is still a pressing issue.
If you follow all the points, you can reduce your gasoline or diesel consumption by 10-15%, which can provide significant savings in the long run.
1. Air streamlining
Of course, this point applies primarily to planing boats. It is logical to assume that elements such as an awning over the cockpit or flybridge create significant resistance even at medium speeds. If they are not needed, then it is better to fold them for the duration of the passage.
2. Angle of attack of the hull
This point also applies mainly to planing boats of small sizes. The hull of each boat has its own optimal driving mode, in which the angle of attack to the water surface plays an important role. A high bow lift, as well as an excessive bow lowering, not only increases fuel consumption, but also has a negative impact on seaworthiness, controllability and safety, and can also significantly complicate entering the planing mode.
For proper balancing on sterndrives and outboard motors, it is necessary to use a trimmer that changes the angle of attack of the propeller, as well as transom plates. If this does not completely eliminate the problem, then it is necessary to redistribute the weight in the boat.
With an increase in the length of the boat and its displacement, this problem becomes less relevant, especially when using inboard direct-drive engines.
3. Leave excess weight on the shore
Reducing the weight of the boat greatly affects fuel economy. But this in no way concerns rescue equipment, anchors, fuel, drinking water and provisions.
4. Clean hull below waterline
This is one of the most important factors. Regular cleaning of the underwater part is mandatory on any type of yacht. Sometimes cleaning the hull below the waterline can increase the speed by several knots at the same engine speed.
5. Engine condition
At least once a year, it is necessary to thoroughly check the engine and peripheral systems, conducting a deep revision with the replacement of consumables and worn parts. A serviceable engine with good compression consumes significantly less fuel than a worn and poorly maintained one.
But the health of the engine is much more important from a safety point of view, because a motor breakdown at sea is not the same as a car breakdown on the road.
6. Slow down!
This is the easiest way to save not only fuel, but also battery power, if we are talking about electric motors. In most cases, regardless of the hull shape, the most profitable is a leisurely movement in displacement mode.
Another thing is that buying a planing cruiser with two or even three powerful inboard engines for this is not entirely advisable. If speed is not your top priority, then it is better to consider highly fuel-efficient trawler-type yachts.
7. Propellers
The propeller must be in perfect condition, as it is the main link between the engine and the water, converting the rotational motion of the shaft into the forward motion of the boat.
The propeller must be absolutely clean, and its edges must not have any damage or dents from impacts and cavitation. Even small dents provide enormous resistance, given the speed of rotation of the blades in the water. In terms of importance, this point is comparable to a clean boat hull.
In addition to cleanliness and integrity, important parameters such as pitch, diameter, blade area, blade thickness and thrust play a determining role in how efficient a propeller will be for a particular type of boat with a particular engine.
Motor yachts are supplied with propellers of optimal parameters, and sometimes with the ability to remotely change the angle of attack of the blades to adjust the pitch. On small boats, you can achieve significant fuel savings by installing a propeller that meets individual requirements for speed, driving mode and boat loading.
However, choosing a propeller requires at least basic technical knowledge and an understanding of the basics of hydrodynamics, otherwise you can not only exceed the current fuel consumption, but also damage the engine. In any case, turning to professionals is often the best solution.
8. Electric motors
This is the best option (if you don’t consider sails) not only for saving fuel (in a hybrid version), but even for forgetting about it and the inconveniences associated with it forever. However, electric motors are ideal for tenders and slow coastal cruising, but they are not yet suitable for all types of boats.
You can easily fit hydrogen generators on a superyacht or pave a catamaran with solar panels, but trawlers and mid-sized planing cruisers cannot yet abandon diesel engines. Another concern for many potential buyers of electric yachts is the large number of lithium batteries, which apparently cannot be called completely safe.
However, given the speed of innovation today, it is safe to assume that scientists will soon come up with something safer and more effective, and engineers will bring it to life.