Seaworthy motor boats | Once across the Atlantic


Long journeys and ocean crossings by sailors are the order of the day today. But is that also possible with motor boats?

Take a break of one, two or three years. And then with your own motorboat to the Channel Islands, Cape Verde, maybe Iceland or even across the pond to the Caribbean? Without a sail, but at a steady speed and regardless of the wind. Is that really possible? Every year many sailing yachts cross the Atlantic. And it goes without saying that sailboats of all sizes are out and about on every sea.

If, on the other hand, you tell an average pleasure boat driver that you want to cross the Atlantic in your own motorboat of the ten to fifteen meter class, then you are usually thought to be crazy.

Travel across the open sea and even oceans by motorboat has a long tradition: As early as 1975, Robert P. Beebe wrote a series of concepts for seagoing motorboats in his classic “Voyaging Under Power”. And he had already put his ideas into practice in his own boat, the “Passenger Maker”, in 1963, and in five years had covered 50,000 nautical miles across all the world’s seas.

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In the meantime, the term “passagemaker” in the USA describes its own boat class: sea-going motorboats that not only survive any weather on the open sea, but also have the range to cross oceans. Prominent examples of this are yachts from Nordhavn and Kadey Krogen.

For example, a Nordhavn 40, barely more than twelve meters long, circled the world once from 2001 to 2002 and covered 24,000 nautical miles in the process.

In Europe, however, the idea of ​​traveling the Baltic Sea, North Sea or even the Atlantic or Pacific in a motorboat between ten and fifteen meters is almost always met with incomprehension. But why should such trips only be possible by sailing boat? There are mainly two reasons. First, the range: the sailboat consumes no fuel and can therefore theoretically travel as far as you want.

Second, the behavior in rough seas: a sail stabilizes the boat in most winds so that it still pounds, but rolls very little – which makes the trip much more pleasant. Motorboats, on the other hand, consume so much fuel according to general opinion that a normal range is measured in hundreds of nautical miles, which is certainly only sufficient for travel close to the coast.

And the swell! Motor boats roll so violently, depending on the wave, that the crew is inevitably seasick or at least so stressed that it is hardly possible to safely drive the boat.

And yet: both points can be turned off surprisingly easily.

A sea-going motorboat consumes little fuel

First about fuel consumption. This depends on two factors: the type of boat, i.e. glider, semi-glider or displacer, and the speed at which it travels. A lot of energy is required to bring a glider or semi-glider up to speed. That’s why they quickly consume 50 liters per hour or more at over 20 knots (i.e. over 2.5 liters per nautical mile).

A common route across the pond is about 2500 nautical miles. At 20 knots you would be there in just over five days, but you would burn around 6250 liters of fuel. That is over six tons of additional weight. And how is a glider supposed to carry so much fuel?

A displacer, on the other hand, can very easily achieve a consumption of one liter per nautical mile or less. And a few tons more weight is much easier to carry for a displacement hull than for a glider or semi-glider.

Then the cruising speed is decisive for a displacer. For example, a 12-meter boat will burn 0.8 liters per nautical mile or less at 5 knots, while the same boat will use 1.2 liters or more at 7 knots. A good compromise is a 6 knot speed with 1 liter consumption per nautical mile. For the above-mentioned route, 2500 liters of fuel are required, the weight of 2.5 tons plus reserve of which the displacement hull can easily support.

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No more swinging

Solidly built displacement motor boats are basically no less seaworthy than sailing boats. For example, Harald Paul is out and about in the northern Atlantic with his Gypsy Life (Smelne) even in strong winds. But that’s only for the very tough. Because with waves several meters high, such a boat rolls so violently that the crew on board quickly becomes completely exhausted and is hardly able to drive the boat.

Therefore, it was already clear to the pioneer Robert P. Beebe mentioned at the beginning that a sea-going motorboat must be stabilized against rough seas and especially against rolling. He has copied a simple but very effective system from American fishermen: the flopper stoppers.

In doing so, constructions (the flopper stoppers) are dragged along in the water on long booms, which sink quickly, but are very difficult to pull up again. If the boat wants to roll because of a wave, one of these flopper stoppers always offers resistance to the rolling movement.

This system works so easily and well that it is still widely used today. For example, on the MY Lena on a trip through the Mediterranean, to the Cape Verde Islands and from there across the Atlantic to the Caribbean, or the MY Kaniva from Germany across the North Sea to Scotland, then to Ireland and across the Atlantic to Newfoundland and back .

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If flopper stoppers are too cumbersome for you, you can use stabilizers in the form of active fins, as we have described them in BOATS 7/15. Fins are installed on the fuselage, which are moved by hydraulics. Electronics in the boat constantly check in which direction the boat wants to roll and control the fins so that they generate an appropriate counterforce. Result: Rolling is reduced by up to 90%.

But only if the boat makes a few knots of speed. Because the fins can only generate a counterforce when they are flown against. Flopper stoppers on booms, on the other hand, also work when the boat is at rest – for example at anchor. Flopper stoppers can do without any electronics or hydraulics. They are therefore relatively quick and cheap to install and there is little that can cause problems with them.

Fins are technically more complex, but they are always ready for use at the push of a button and can adapt well to the respective sea state. Each principle has its advantages and disadvantages, but in any case the unpleasant boat movements in the sea can be reduced so effectively that passages lasting days or even weeks are no longer agonizing, but comfortable and pleasant.

The advantages of the motor boat

Now that fuel consumption and swell are no longer obstacles, the advantages of the motorboat, especially on long passages across the open sea, can be enumerated:

• Great independence from wind and weather
• Constant travel speed and thus predictable arrival times
• There is always enough energy available for life on board

The wind is particularly important. A lull on a sailing boat means standing still and quickly drains your nerves. And when the wind blows, it is often from the wrong direction, so that the course has to be changed and a passage can quickly take a few days longer.

With the motorboat, however, a direct course can be taken. Days with little wind are not annoying, but promise a quiet journey and are therefore usually very welcome.

The cruising speed is not always the same even when the engine is running: Wind, swell and currents can make the boat faster or slower. The deviations are usually comparatively small, however, and the boat reliably drives towards its destination. Of course, a long passage loses the character of being fully dependent on the elements. Everyone can decide for themselves whether that is bad or good.

In any case, it is very practical that the batteries do not have to be charged by more or less reliable wind power or solar cells: the machine is running anyway and produces electricity in abundance. It is stored in the batteries.

flopp stoppers 2
flopp stoppers

One or two machines?

One thing is clear: if the machine is the only drive in the middle of a large sea, possibly with a lot of wind, fails, this can lead to unpleasant situations and even distress. So does a sea-going motorboat necessarily have to be equipped with two engines?

Many ocean crossers prove otherwise. The Lena, the Kaniva or the Gypsy Life – they all only have one diesel engine.

And with good reason: a well-cared for and maintained marine diesel engine in operation can only bring very little to a standstill as long as clean diesel and sufficient cooling and oil are available.

For the clean diesel there are double filter systems and day tanks. And the other problems that can arise on the road can almost always be solved with suitable spare parts and a little manual skills. As an alternative, motorboats for the higher budget often have a so-called “coming home” machine: a small, second diesel engine with its own propeller that keeps the boat maneuverable in an emergency and allows short trips. Ultimately, however, this machine is almost always standing around unused and still needs a lot of care and maintenance so that it really works if the worst comes to the worst.

Everyone has to decide for themselves and their wallet whether and when this makes sense. The mentioned practical examples show that it can also be done without.

Get anywhere with your own motorboat

But there are a few more important properties that sea-going motorboats should have. A machine room with a lot of freedom of movement, for example, enables regular checks while on the move. A reliable autopilot should also be on board, because nobody wants to steer for days. However, lower fuel consumption and stabilization in rough seas are decisive.

Then the trip over a sea or even an ocean is of course still real seafaring with all its challenges in terms of nautical and navigational skills. But it is not only possible with a suitable motorboat, it can even be very pleasant.

And so, destinations like the Channel Islands, Iceland or the Caribbean mentioned at the beginning can also be reached with a motor cruiser – comfortably and safely.

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