The fastest sailboat in the world. Sailing extreme

WIND DRIVING FORCE

The NASA website has published very interesting materials about various factors influencing the formation of lift by an aircraft wing. There are also interactive graphical models that demonstrate that lift can also be generated by a symmetrical wing due to flow deflection.

The sail, being at an angle to the air flow, deflects it (Fig. 1d). Coming through the “upper”, leeward side of the sail, air flow travels a longer path and, in accordance with the principle of continuity of flow, moves faster than on the windward, “lower” side. The result is that the pressure on the leeward side of the sail is less than on the windward side.

When sailing on a jibe, when the sail is set perpendicular to the direction of the wind, the degree of increase in pressure on the windward side is greater than the degree of decrease in pressure on the leeward side, in other words, the wind pushes the yacht more than it pulls. As the yacht turns sharper into the wind, this ratio will change. Thus, if the wind is blowing perpendicular to the yacht's course, increasing the pressure on the sail on the windward side has less effect on speed than decreasing the pressure on the leeward side. In other words, the sail pulls the yacht more than it pushes.

The movement of the yacht occurs due to the fact that the wind interacts with the sail. Analysis of this interaction leads to unexpected results for many beginners. It turns out that the maximum speed is achieved not at all when the wind blows directly from behind, and the wish for a “fair wind” carries a completely unexpected meaning.

Both the sail and the keel, when interacting with the flow of air or water, respectively, create lift, therefore, to optimize their operation, wing theory can be applied.

WIND DRIVING FORCE

The air flow has kinetic energy and, interacting with the sails, is capable of moving the yacht. The work of both the sail and the airplane wing is described by Bernoulli's law, according to which an increase in flow speed leads to a decrease in pressure. When moving in the air, the wing divides the flow. Part of it goes around the wing from above, part from below. An airplane wing is designed so that the air flow over the top of the wing moves faster than the air flow under the bottom of the wing. The result is that the pressure above the wing is much lower than below. The pressure difference is the lifting force of the wing (Fig. 1a). Thanks to its complex shape, the wing is able to generate lift even when cutting through a flow that moves parallel to the plane of the wing.

The sail can move the yacht only if it is at a certain angle to the flow and deflects it. It remains debatable how much of the lift is due to the Bernoulli effect and how much is the result of flow deflection. According to classical theory wing lift arises solely as a result of the difference in flow velocities above and below the asymmetrical wing. At the same time, it is well known that a symmetrical wing is capable of creating lift if installed at a certain angle to the flow (Fig. 1b). In both cases, the angle between the line connecting the front and rear points of the wing and the direction of flow is called the angle of attack.

Lift increases with increasing angle of attack, but this relationship only works at small values ​​of this angle. As soon as the angle of attack exceeds a certain critical level and the flow stalls, numerous vortices are formed on the upper surface of the wing, and the lift force decreases sharply (Fig. 1c).

Yachtsmen know that gybe is not the fastest course. If the wind of the same strength blows at an angle of 90 degrees to the heading, the yacht moves much faster. On a jibe course, the force with which the wind presses on the sail depends on the speed of the yacht. With maximum force, the wind presses on the sail of a yacht standing motionless (Fig. 2a). As speed increases, the pressure on the sail drops and becomes minimal when the yacht reaches maximum speed (Fig. 2b). The maximum speed on a gybe course is always less than the wind speed. There are several reasons for this: firstly, friction; during any movement, some part of the energy is spent on overcoming various forces that impede movement. But the main thing is that the force with which the wind presses on the sail is proportional to the square of the speed of the apparent wind, and the speed of the apparent wind on a gybe course is equal to the difference between the speed of the true wind and the speed of the yacht.

With a gulfwind course (at 90º to the wind), sailing yachts are able to move faster than the wind. In this article, we will not discuss the features of the apparent wind; we will only note that on a gulfwind course, the force with which the wind presses on the sails depends to a lesser extent on the speed of the yacht (Fig. 2c).

The main factor that prevents an increase in speed is friction. Therefore, sailboats with little resistance to movement are able to reach speeds much higher than the speed of the wind, but not on a gybe course. For example, a boat, due to the fact that skates have negligible sliding resistance, is capable of accelerating to a speed of 150 km/h with a wind speed of 50 km/h or even less.

The Physics of Sailing Explained: An Introduction

ISBN 1574091700, 9781574091700

Back in the early fifties, many yachtsmen were prejudiced against installing a gasoline or diesel engine on a sailing yacht. The engine on the yacht was considered a completely useless and even dangerous (from a fire point of view) cargo; argued that the motor tends to fail at the most critical moments. Most yacht captains called the union of a motor and a sail unnatural.

Now the situation has changed. It is difficult to find a cruising yachtsman who would deny the need to install an auxiliary engine. The vast majority of cruising yachts are equipped with motors, if not during construction, then during subsequent conversion.

A motor is, of course, necessary when the yacht has to enter the harbor along a narrow, winding channel, tacking against a headwind. People involuntarily remember him even when the sails hang helplessly, and you urgently need to return to the yacht club, going against a strong current. What about anchoring and unanchoring in narrow places, crossing canals and under bridges, sailing in calm weather? In all these cases, the motor not only makes maneuvering easier, but also saves time, which can then be used to go a hundred miles further or to explore the sights on the shore.

Tourists sailing on boats, on the contrary, often have a desire to set sails in order to use the fresh tailwind, save fuel, and simply take a break from the constant noise of the engine and vibration.

Below we discuss the features of combined motor-sailing vessels, combining the qualities of a sailing yacht and a boat. The two extreme poles of such combined vessels are a yacht with a low-power auxiliary engine and full sail rig, and a boat with a powerful engine and auxiliary sail (mainly to give the vessel stability on rough seas). The intermediate type vessels discussed in this article will be further referred to as motor sailboats.

Boat and yacht. It is easy to compare the main operational qualities of a motor boat and a sailing yacht in the form of a table. 1.

Table 1. Comparison of the main qualities of a sailing yacht and a boat

When designing a motor sailboat, the goal is to achieve high speed, both under the engine and under sail, and maintain a shallow draft of the boat, which makes many shallow harbors and bays accessible. A sailing yacht must maintain high seaworthiness, efficiency and a long cruising range, as well as good conditions habitability.

In coastal cruising, a keel yacht (7-10 m long) without a motor shows an average speed during the transition from 3 to 5 knots. On a motor sailboat, you can get a stable average speed of 3-4 knots more, which allows you to travel an extra 50-80 miles per day; there is no need to tack in a weak headwind or wait out calm hours at sea. On the other hand, if the boat crew is often forced to refuse to go out to sea, especially in strong headwinds and large waves, a motor sailboat can safely go into a steep close-hauled sail under reefed sails.

How in the best possible way combine in one vessel positive qualities? Would it be right to install a powerful engine on a sailing yacht or a developed sailing rig on a boat?

It is known that a sailing ship can develop an acceptable speed if its sail area S (m²) is in a certain ratio with the displacement D (m³) and the wetted surface Ω (m²). These ratios should not be less than:

S 1/2 /D 1/3 = 3.8÷4.2; S/Ω = 2÷2.5,

and the first of them characterizes the performance of the yacht in strong wind, and the second - in weak.

The yacht will be able to carry such an optimal windage if it has good stability, which is ensured by a deeply submerged heavy false keel (its weight is 35-50% of the total displacement). Naturally, when sailing under a motor, such stability is not needed, and “transporting” a false keel will require an unproductive expenditure of engine power; In this case, the spar, sails and equipment become the same useless cargo.

To create sufficient resistance to drift, the yacht's hull must have a large area of ​​lateral resistance (14-18% of the sail area). Therefore, the wetted surface of the yacht’s hull is larger than that of a boat of the same dimensions, and to achieve the same speed as the boat, more motor power will be required. The developed equipment and spars of the yacht increase air resistance, which also requires the expenditure of additional power to overcome. The contours of the yacht, designed for sailing at a relatively low speed and with a list, do not allow the motor to develop a higher speed, no matter how much its power is increased.

On the other hand, if you put the sailing rig of a yacht of the same size on the boat, the result is unlikely to be satisfactory. Due to the absence of a false keel and the high location of heavy loads (engine, fuel reserves, developed superstructures), the stability of the boat will be clearly insufficient for sailing and a reduction in the sail area will be required. It will not be possible to sail steeply into the wind, since the lateral resistance of its body is small. The contours of its underwater part are not designed for swimming with a roll and drift. A propeller with a large diameter and wide blades will greatly slow down sailing. And the hull of the boat itself, designed to move at a single and fairly high speed, will have more resistance than the hull of the yacht.

From what has been said, it is clear that a boat under sail will not be able to achieve the same tacking and sailing qualities as a yacht, just as a yacht with a powerful engine will not be able to achieve the speed of a boat of the same size and with an engine of the same power. When designing a motor sailboat, you need to find a compromise between these types of vessels and give preference to one or another individual qualities.

Features of the movement of displacement vessels at high speed. Every yachtsman certainly knows that when a yacht moves, waves form around its hull. The height and length of these waves increase as the speed of the yacht increases (Fig. 1), and their number, which fits the length of the vessel, decreases. Sometimes you can see how racing yachts, for example, class "P-5.5", sail on only one wave (the adjacent crests are located in the bow and stern, and the sole is near the midsection). This position means that the yacht has reached its maximum speed if its weight, contours and sail area do not allow it to go into planing mode. It seems that the ship is unable to climb the crest of the wave that it itself created. Nevertheless, light yachts - “Flying Dutchmen” and “stars” - in a fresh wind can overcome this barrier and plan, being only on one ridge, which is now located near the midsection. Similar phenomena are observed on boats with a gradual increase in their speed.

It is easy to notice that the pattern of wave formation depends not only on the speed of travel, but also on the length of the vessel: the shorter the vessel, the lower the speed the wave barrier phenomenon is observed. Therefore, in shipbuilding, the speed of ships is usually characterized by relative speed, or Froude number,

where v is the speed of the vessel, m/sec; L - length along the waterline, m; g is the acceleration due to gravity, equal to 9.81 m/sec², √ is the square root.

This value characterizes, first of all, the intensity of wave formation near the hull at a given speed and the proportion of motor or sail power required to create these waves. For example, if a yacht is said to be sailing at a speed of Fr = 0.29, the boatbuilder knows that regardless of its length:

There are approximately two transverse bow waves along the length of the yacht;

The power required to create waves is about 50-60% of the total required engine power (the rest is spent on overcoming the friction of the hull skin on the water and the vortex resistance of the hull).

In the same way, when the Froude number Fr = 0.4÷0.5, the moment comes when the ship rides on two adjacent crests of the same wave, and the resistance to movement from wave formation reaches 90% of the total resistance of the hull. This speed represents the very barrier that can only be overcome by light planing yachts or boats with appropriate contours and engine power. In Fig. Figure 2 shows a graph of the dependence of the yacht's resistance (in the form of the towing power required to overcome it) on the relative speed. It can be seen that in the range Fr = 0.3÷0.5 the resistance increases sharply with the slightest increase in speed. That is why the power developed by the sails is usually only sufficient to achieve a certain speed v = 2.2÷2.4√L knots. (which corresponds to the relative speed Fr = 0.38÷0.39). It is obvious that increasing the speed of a yacht under motor beyond this limit without any change in contours and reduction in displacement will require an exorbitant increase in engine power, and consequently, an increase in its dimensions and weight, fuel reserves and displacement of the vessel as a whole.

Therefore, the speed of motor sailboats under power usually does not exceed the value v = 2.7√L. At this speed, you can get a satisfactory compromise between sailing performance and performance under the motor.

In table Table 2 shows the maximum and economic speed values ​​for motor-sailing yachts of various lengths according to the waterline.

Table 2. Economic and maximum speeds of motor sailers

When a vessel moves at a speed above v = 2.7√L (Fr = 0.45), it forms, as already noted, a wave whose length exceeds the length of the vessel, and the apex is located near the amidships of the vessel. Such a wave causes the vessel to trim aft, which in turn leads to an increase in the stern wave and, ultimately, to sharp growth resistance of water to the movement of the vessel. In order to counteract trim, the stern of the vessel must have a wide transom and a flat bottom with gently sloping, almost horizontal buttocks. Thanks to this shape of the hull, a lifting force is created on the bottom, which levels the vessel, and with a further increase in power, squeezes it out of the water, putting it in planing mode.

However, such stern contours are unacceptable for a motor sailboat, since when sailing with a list (under sails), the large volume of the stern causes a trim to the bow; As a result, the hull and keel of the yacht occupy the wrong position (angle of attack) when tacking and do not allow sailing steeply to the wind, and the flow formed behind the stern slows down the movement of the yacht.

Thus, having considered the peculiarities of the movement of heavy displacement vessels, which are usually tourist boats and yachts, we can draw the following conclusions:

The maximum achievable speed under sail for yachts is v = 2.2÷2.4 √L knots;

The engine power for a motor-sailing yacht with good tacking qualities should not exceed the value necessary to develop a speed v = 2.7 √L knots;

If a boat is designed for high speed under power, it cannot be expected to have satisfactory tacking ability.

Types of motor sailboats. Depending on the speed developed under the motor and the role assigned to the sail or motor on a given vessel, all motor-sailing yachts can be divided into four main types.

I. Yachts with auxiliary engine. These are essentially ordinary cruising yachts on which the engine plays minor role and is installed solely to facilitate entry and exit from the harbor, passage along the fairway, mooring, etc. The motor is selected with minimal power, weight and dimensions. The speed under the motor in these cases does not exceed the value v = 1.8÷2.0 √L knot. (5-6 knots for most cruising yachts). The fuel reserve is also small, usually 20-30 hours. continuous engine operation, i.e. 100-200 miles.

To reduce resistance when moving under the motor, the propeller must have a minimum permissible diameter and narrow blades; Usually the propeller is placed in the window of the sternpost and rudder.

The power of the auxiliary engine to achieve the specified speed is usually 1.2÷2.0 liters. With. per 1 ton of yacht displacement. The weight of the motor does not exceed 3% of the displacement D, and the weight of the fuel reserves is 2% D. Therefore, installing the engine does not affect either the stability of the yacht or its tacking qualities. The weight of the false keel is maintained within 35-45% D.

II. with preference to sailing qualities. When designing ships of this type, the designer usually strives to combine good tacking qualities and sailing performance with a relatively high speed under the engine. One of these sailboats is shown in Fig. 3.

Motor sailboats of this type differ from yachts with an auxiliary motor by a more powerful motor (4÷5.5 hp/t) and, therefore, a higher speed under the motor (2.2÷2.4√L knots), and also an increased cruising range under motor (up to 800-1000 miles for a yacht about 15 m long). Here the engine plays the same basic role as the sails, so greater attention is paid to performance under the engine. This type of yacht is often called “50/50” (i.e. 50% each of a yacht and a boat).

In Fig. Figure 4 shows a theoretical drawing of a motor sailboat, the main elements of which are indicated in table. 3 (for comparison, data on a type I yacht and a seaworthy boat with the same length according to the waterline are shown next to it).

Table 3. Comparison of vessels of the considered types

The contours of this motor sailboat are characterized by a shallow draft, short overhangs, a straight keel line, and a wider transom stern than usual on yachts. The camber of the frames in the bow and the outlines of the deck line are typical for motor yachts. The waterlines in the bow have more acute angle entrance (pointed), and the buttocks in the stern rise at a smaller angle to the waterline than on a sailing yacht.

Due to the installation of a powerful diesel engine, the weight of the false keel was reduced to 30%D. The propeller is located in a large sternpost window, behind the vertical star post and has a significant diameter. This placement of the propeller helps to increase its efficiency and more fully utilize the power. Naturally, the reduced stability, as well as the trimmed underwater part of the DP, does not allow for full sail. On larger yachts of this type, a centerboard is often installed to improve tacking qualities. The option with a centerboard is a good compromise between the sail and the motor: when sailing under the motor, the centerboard can be removed and thereby reduce the wetted surface of the hull.

To reduce air resistance when sailing, the volume of superstructures is sought to be reduced to a minimum.

Among the relationships characteristic of this type of vessel, another parameter can be noted:

S 1/2 /D 1/3 = 3.5÷3.9,

while for type I yachts this value is larger (3.8÷4.4).

III. Motor-sailing yachts with a preference for boat qualities. In this case, the speed under the motor plays a primary role and reaches v = 2.7÷2.9 √L knot. As already noted, at this speed the vessel gets a strong trim aft, so a wide transom stern with flat buttock lines is preferable. The required engine power increases to 6.5÷9 hp/t, which forces the weight of the false keel to be reduced to 15-25% D.

The draft is taken such as to accommodate a propeller of the required diameter (usually T=11÷13% L).

Since the shape of the hull still turns out to be unsuitable for steep tacking, they abandon the installation of a centerboard and increase the volume of superstructures. The sail area is relatively small:

S 1/2 /D 1/3 = 2.8÷3.4.

Sails are intended mainly for sailing full courses in fresh winds and stabilizing the movement of the yacht on rough seas.

An example of a vessel of the type under consideration is the Serch (Fig. 5 and 6), a seaworthy yacht designed for long voyages. It has good performance both under motor and under sail. The main elements of the yacht are given in table. 4 (next for comparison are the data of the yacht with the Khortytsya auxiliary motor).

The yacht's hull, in terms of its contours, approaches the shape of a seaworthy boat (straight keel line, short overhangs, high freeboard, stern with a wide transom partially submerged in the water). The propeller with a diameter of 850 mm is located behind the sternpost in a large window.

“Serch” carries half the sail capacity of a yacht with an auxiliary motor. The sails are relatively wide, with a low center of sail, designed for full course sailing.

Table 4. Comparison of two representative vessels

IV. Boats with auxiliary sails. If the boat is intended for sailing at sea or on big lake, it makes sense to install small-area sails on it, first of all, to improve seaworthiness on a wave (primarily to increase stability on course, soften pitching and give the ability to drift). In a fresh wind, the boat can sail (without a motor) at low speed into the backstay or even tack, powered by the engine. The sail area is assumed to be about 5 m²/t for boats with a displacement of up to 5 tons; 4÷3 m²/t for boats with a displacement of 5-10 tons and 2.5÷3 m²/t for large vessels.

As an example, let’s take the seaworthy boat “Passagemaker” (Fig. 7 and 8), designed for long-distance sea and ocean voyages. The engine power is small - only 40 hp. With. (1.6 hp/t); the speed is correspondingly low - 7.5 knots (2√L), but the fuel reserve is 5.5 tons (22% D), which provides a huge cruising range - 2400 miles. Only 2.3 kg of fuel is consumed per mile traveled.

The greatest length is 15.3, and along the vertical line - 14.0 m; beam 4.9 m, draft 1.53 m, displacement of the Passagemaker 25 tons, and the weight of the false keel is only 3.3 tons (13% D). The sail area is about 50 m².

The contours of its hull are typical for motor seaworthy yachts with low speed (sharp waterlines in the bow, a bottom with a large deadrise at the transom, a straight keel line). High freeboard and extensive superstructures are also typical. This theoretical drawing can be taken as a basis for designing a motor sailboat of shorter length (9-10 m).

It should be noted that yachts of this type are often equipped with low bilge keels, which significantly reduce drift under sail and, in addition, serve as effective roll dampers.

D. A. Kurbatov, 1966

Many people often ask this question before setting off on a long voyage. This is understandable.
Motor yachts are characterized first of all by the type of engine, and then by the concept of the hull, which can be displacement, a hybrid between displacement and glider and different gliders, which determines the speed, and often the convenience, safety and method of using the vessel. Small recreational powerboats are equipped with one main engine and a small, usually external, auxiliary unit, while larger boats typically have two engines for better seaworthiness and greater safety.
Sailing yachts are characterized by a displacement hull with a ballast keel, mast, sails and auxiliary engine.
Recently, double-hulled yachts - catamarans - have become increasingly popular - stable, relatively fast, extremely comfortable and safe vessels with up to eight beds, convenient for travel large families or groups of friends.

Yacht speed

Motor yachts

The most significant difference between sailing yachts and motor vessels is speed, maximum and operational. Modern motor yachts, and even boats, based on the concept of the hull and engine power, are designed and built in order to achieve high speeds from 15 to 70 knots. Meanwhile, vessels with very high speeds are difficult to find in the offers of charter companies, since the average speed of the proposed vessels is about 20 knots. This is enough for pleasant sailing and exhilarating planing.
It should be said that planing is not only a matter of pleasure, but also of economy, since the resistance of the hull of a planing vessel is significantly less than that of a conventional displacement vessel. A glider with its high speed allows you to leave Split in the morning, spend until noon swimming in some Croatian bay, run to Vis for lunch and return to the island of Korcula for the night.
However, this advantage of motor yachts is associated with disadvantages: waves hitting the hull of the vessel at high speeds, vibration, engine noise, the smell of exhaust gases, etc.

Sailing yachts

The speeds that sailing yachts reach are determined by the conditions of their purpose. Slow due to moderate sail surface area and a heavy hull designed for crew comfort rather than speed enjoyment, the yachts sail at speeds of 5 to 10 knots. This means that in five hours of active sailing you can cover about 40 miles, which must be taken into account when planning your trip. The advantages of the Adriatic Sea, rugged shores with numerous islands and a short distance between stops during the planned voyage allow one day to have enough time for sailing, enjoying sailing in favorable winds, swimming in some bay and, accordingly, spending the night in a nearby place. This category of vessels is designated special philosophy life at sea: speed is not important, but contact with the sea, wind and nature is important. It is good to sail in light winds at a speed of 2-3 knots. Sailing like this is a recipe for relaxation, listening to the sound of the sea, without engine noise or exhaust smells. For the experienced and brave, who do not lower the sails or reduce their area in winds above 20 knots, sailing turns into an adrenaline-filled adventure.
The speed of sailing depends on weather conditions, wind as propulsion, waves and currents. At the same time, the engine with a power of 30 to 100 kW is designed for maneuvers in port, sailing in complete calm or for avoiding stormy weather.

Yacht fuel consumption

Motor yachts

Speed ​​is paid for in fuel consumption. For example, two 250 kW diesel engines can consume more than 100 liters of fuel per hour, depending on the operating mode. For example, the motor yacht Princess 52, equipped with two 610 kW engines, sailing from Split to Dubrovnik via Hvar with average speed 20 knots, will consume fuel for 7000 kuna (about 1000 euros). Therefore, when chartering a motor yacht, you should be sure to pay attention to the stated fuel consumption of the yacht, as the cost of the fuel costs you will need can get dangerously close to the cost of renting the vessel.

Sailing yachts

When operating a sailing yacht, the cost of fuel is negligible. Usually the amount is about 700 kuna (about 100 euros) for a whole week. Of course, the final result depends on how many hours you have spent under the engine, how much you have sailed and whether the winds have been favorable. In the summer on the Adriatic, the afternoon mistral is almost constant, and if the yacht has at least a slightly trained crew, then you can easily sail at the highest speed that the design features of the yacht allow you to develop. However, if circumstances force you to use the engine more than previously planned, there is no need to worry. Fuel consumption on yachts is modest.

Autonomy

Motor yachts

Due to the high fuel consumption, the endurance (distance in miles covered with a full tank of fuel upon departure) is much less than that of sailing yachts. In practice, this means that you will have to fill up at the gas station more often, which can be extremely difficult during high season due to queues. Sometimes you have to wait more than an hour. Since receiving fuel can take about twenty minutes, as 1000 liters or more are often poured in, it is better to approach the gas station early in the morning, when it opens.

Sailing yachts

With one full tank (usually about 100-200 liters) you can travel for a whole week. In practice, this means that you hire a yacht, leave with a full supply of fuel, and then buy fuel at the end of a seven-day voyage if the contract requires you to return the yacht with a full tank. If, with favorable winds, you will be sailing for a week, the engine will only be used for maneuvers in marinas and, possibly, to recharge the batteries.
You may recall that many yachtsmen have sailed around the world even on relatively small yachts, which is impossible on a large motor yacht without refueling.

Maneuverability features

Motor yachts

The planing bottom of a motor yacht is designed to achieve high speeds. In the open sea on large waves, especially from the side or from the stern (if you sit on a wave), the yacht does not maintain a good course, causing roll. In this case, more powerful engines that can cope with the force of the waves help. The more powerful the engines, the greater the stability of the vessel, and the faster you can avoid possible bad weather.
When leaving and entering marinas, motor yachts with two engines are very easy to control, since by operating one engine forward and the other astern, the vessel can be turned around in place. Moreover, larger motor yachts have electric bow thrusters. Therefore, maneuvering even in cramped marinas is a real pleasure.
Problems arise in strong crosswinds, when, due to low speed, the vessel is severely drifted, since the underwater part of the vessel, which could resist drift, is much smaller than its surface part, which is exposed to the influence of the wind. In this case, the maneuver must be carried out quickly and decisively, and this requires experience.

Sailing yachts

Yachts are designed and built on the idea of ​​less resistance to the underwater part of the hull and greater stability under the influence of wind and waves. Due to the low center of gravity, the heavy ballast keel provides the yacht with stability and reduces wind drift, as it acts as a “submerged wing”. In addition, by increasing and decreasing the area of ​​the sails, that is, by influencing the force of the wind, you can adapt the speed of the yacht to the state of the sea, adhering to the rule that high speed adds stability in rough seas.
Maneuvering a sailing yacht in a marina is different from maneuvering a motor yacht. One engine compared to two on a motor yacht is a disadvantage. However, thanks to the keel, which is the center of rotation of the underwater part of the hull, and the position of the propeller, usually offset by one third of the hull length from the stern, sailing yachts in ports are very agile.
They are also little disturbed by side winds due to the favorable ratio of the underwater part of the vessel and the freeboard. If a yacht has a bow thruster, its maneuverability improves.

Comfort

Motor yachts

In addition to speed, characteristic features motor yachts are comfortable, luxurious interior finishing, large decks for sunbathing, separate rooms on the forecastle. There is more space at the stern of the vessel (cockpit) than on sailing yachts. There is usually a large table and chairs for relaxing and eating. Passengers launch into the sea from an aft platform that is more spacious than a sailing yacht, if it even has one. Motor yachts usually have an overhead command bridge, which makes it possible to combine relaxation and control of the vessel with exploring the wonderful surroundings. Interior decoration high quality using quality fabrics and leather. The decks are teak and often carpeted, the cabins are spacious and equipped with large bathrooms, the kitchen is larger and better equipped: microwave, additional refrigerator, ice maker...
Increasingly, motor yachts are equipped with climate control systems, electronics for entertainment, that is, everything that makes the trip enjoyable. For all these energy consumers, a generator is located in the engine room, which provides home comfort at sea. Motor yachts, as large energy consumers, often cause voltage drops in marinas, so it is recommended not to use all energy consumers at the same time.

Sailing yachts

Modern sailing yachts are closer in comfort to motor yachts, but on them comfort is still subordinated to the purpose of sailing. The bow deck is narrow and not suitable for sunbathing to the same extent as on a motor yacht, in addition, there are different ends for sail control. In the cockpit, due to the sheet guides and winches, there is relatively little space for a table, although the comfort below decks approaches that of motor yachts. Comfortable double cabins, salon, kitchen with gas stove, oven, refrigerator, toilets with showers. Recently, modern models are equipped with televisions and heating or air conditioning systems, as well as diesel generators.
However, the main factor influencing the (un)comfort of a sailing yacht is its position under the sails: the list can reach 45º and everything on the ship is “on its side”. Poorly secured things will fly around, and moving around the deck is quite difficult, since you have to walk on slanted surfaces. To be able to cook food in such conditions, the stove is mounted on a cardan shaft, allowing it to be in horizontal position when the yacht rolls. You should pay attention to the side and deck windows: if they remain open, there is a risk of flooding of the interior while at sea.

Yacht rental price

Motor yachts

The cost of renting motor yachts is much higher than sailing yachts due to their higher cost. The rental deposit is also higher. Of course, maintaining a motor yacht requires more labor and costs more than sailing yachts, especially due to the powerful engines that operate at high speeds to achieve high speeds. The amount of additional equipment and supplies also causes the price to go up. The last thing not to forget is the cost of fuel, which also increases the overall rental cost. This ultimately reaches several tens of thousands of euros per week of rent.

Sailing yachts

The cost of renting a sailing yacht is significantly lower. Lower fuel costs too. Therefore, sailing yachts are hired much more often than motor yachts. Typically, a family of 4 people can expect 3-4 thousand euros per week of rent with all additional expenses.

The season of vacations, travel and adventure is just around the corner. Lovers of water recreation will find the sea or ocean, resorts and beaches, large marinas and small marinas. Some will prefer the Croisette and spend time with a light beach cocktail, others will choose scuba diving and the endlessly amazing underwater world, and someone will give free rein to their inner to the sea wolf(or she-wolf) and go on a free, personal, independent journey on a charter yacht under the hot Adriatic sun.

But how to decide on the choice of yacht? Do we want to sail towards the horizon, catching the tailwind with our sails raised, or will we rush through the waves on a boat with a powerful diesel engine? The choice of yacht for charter depends entirely on our preferences and wishes. However, there are only three options: sailing yachts, which are perfect for family and active recreation, catamarans - double-hulled, relatively fast, comfortable and safe vessels, and motor yachts - for lovers of speed on the water and luxury. So which yacht should you choose?

Sailing or motor?

The main difference between sailing and motor yachts is speed. Modern motor yachts with powerful diesel engines can reach speeds from 10 to 60 knots, i.e. from 18.5 to 111 km/h. In the open sea on a large wave, especially if the wave is from the side or from the stern, the motor yacht does not hold its course well, swaying and causing roll. In this case, powerful engines come to the rescue, helping to cope with the force of the waves. The more powerful the engines, the greater the stability of the vessel, and the faster you can avoid possible bad weather.

However, speed is paid for by increased fuel consumption. For example, two 650 hp diesel engines, depending on the operating mode, can consume more than 100 liters of fuel per hour. Real example: motor yacht Princess 52, equipped with two 710 hp engines, sailing from Split to Dubrovnik (seaside towns in Croatia) at an average speed of 20 knots (37 km/h), will consume approximately € 1,500 in fuel. In practice, this This means that on such a yacht you will have to refuel at a gas station more often, which is usually extremely difficult at the height of the season due to queues. You will often have to wait in line for more than an hour. Therefore, if you rent a motor yacht or a large boat, you should definitely pay attention to the average fuel consumption, since the cost of fuel can get dangerously close to the cost of renting a boat.

Sailing yachts

The speeds that sailing yachts are capable of developing are determined by the conditions of their purpose. Cruising sailing yachts are designed primarily to provide maximum comfort for the crew. Due to the relatively small surface area of ​​the sails, a classic cruising yacht sails at speeds of 5 to 10 knots (9.3 to 18.5 km/h). This means that in six hours of active sailing, the yacht can cover approximately 50 nautical miles, which should always be taken into account when planning a route.

This category of ships is marked by a special philosophy of life at sea: speed is not important, but contact with the sea, wind and nature is important. Yachtsmen love the Adriatic not only because clean sea. The Croatian part of the Adriatic coast has many islands and highly indented coastline with a large number of sheltered bays and harbors with comfortable marinas for safe anchorage of yachts.

Short distances between anchorages allow you to have enough time in one day to enjoy sailing, swim in some picturesque bay and have the opportunity to stop overnight in a place you like. And this is undoubtedly important. Sailing in a light wind at a speed of 2-3 knots, without engine noise and exhaust smells, enjoying the sun and sea - what could be better! The engines that power sailing yachts and catamarans with a power from 30 to 100 kilowatts are designed for maneuvers during moorings, sailing during complete calm or for avoiding stormy weather.

When sailing on a cruising sailing yacht, fuel consumption and consumption are usually quite insignificant. On average it is about 100-120 euros per week. Fuel consumption, of course, may fluctuate slightly depending on sailing conditions and your preferences, the main thing is that the more often the boat is sailed, the lower the fuel consumption. With a full fill of about 100-200 liters (depending on the model of the vessel), you can travel for a whole week.

In practice, this means that you rent a sailing yacht, leave with a fully filled fuel tank, and only pay for the fuel consumed at the end of the seven-day voyage. If the wind blows favorably during the voyage, and you sail all week, then the engine will only be needed for maneuvers in ports and for recharging batteries. As you know, many yachtsmen have traveled long distances, traveling around the world even on relatively small sailing yachts, which is impossible to do on a large motor yacht without constant refueling.

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AB Yachts is one of the few shipyards in the world specializing in the construction of yachts with water jet propulsion. Moreover, the yachts are not small: the shipyard’s most compact model today - AB 58 - is 17.7 m long, the largest - AB 140 - more than 40 m! Let's talk about it, because when a relatively small boat develops a speed of more than 50 knots, it is impressive, invigorating, but not amazing. But when the same thing is demonstrated by a huge yacht with a length of 140 feet and a displacement of 130 tons, there is a completely different interest, and you want to understand the yacht, and not limit yourself to interjections when talking about it. AB 140 appeared in the shipyard's portfolio in 2008, and since then more than one hull has been built on this project - both for private ownership and for charter (the issue price is about 125,000 euros per week excluding taxes), and all yachts are different. With such a length and displacement, yachts are already built according to the semi custom principle, when the layout, finishing and equipment inside the serial hull can be as His Majesty the Customer wishes. Yachts of the same design have different locations and numbers of cabins; they differ in engines, technical saturation, fuel and water reserves and, of course, interior design.

High speed and water cannons are not all the advantages of this yacht

Here is just one example of what a serial, but not standard AB 140 can look like. But first, let’s take a look at the silhouette of the yacht: it will say a lot about what is inside. Extremely smooth, with a medium-sized superstructure and a small flybridge, the profile of the AB 140 clearly demonstrates the idea of ​​sportiness, implemented in the dynamic capabilities of the yacht. As an alternative, this boat can be made without a flybridge at all, with an opening “roof” over the salon - this is exactly what the debut model AB 140 was like. Let’s also pay attention to the huge deck spaces in the bow and stern: “beaches” of this size are rarely seen on yachts with with these dimensions. First of all, because on most superyachts the main deck accommodates, in addition to the salon, a master cabin. That’s why the superstructure is made larger, sacrificing aerodynamics and cutting down the area of ​​the bow rest area. It’s worth looking inside to see that on the AB 140, all (or almost all) of the enclosed space on the main deck is truly dedicated to the salon. The interior, made in monochrome gray-brown tones, looks decent; the furniture is made of ultra-light composite materials and assembled using a special structural adhesive, and all together is in complete harmony with the aggressively sporty, almost futuristic exterior design of the yacht. Although it would be strange to expect Empire style cabinetry on such a boat, the interior is still closer to the classical style than to the increasingly popular modern minimalism. The salon is visually separated from the remaining areas of the superstructure by a light semi-bulkhead (with passages on the sides) that does not reach the ceiling, into which a media center with a 50-inch screen is mounted. Next is a dining room for 10 people and a control station raised on a podium with three individually adjustable chairs.

There are exits to the deck on both sides of the helm station, making it easier for the crew to move around the boat without disturbing guests. There is also a ladder leading down to the bow of the boat, where the galley and crew compartment are located. The latter includes four cabins (the captain has a separate one), the same number of toilet rooms and a dining room for the crew. The lion's share of the main deck area is occupied by the aft cockpit. There is a monumental lounger combined with a sofa section, a dining table, armchairs and a bar counter with high stools. The second, no less significant open seating area is located at the bow: another sun lounger, sofa and table. Moving between bow and stern is easy, even when the AB 140 is moving in full swing: the boat has a very high bulwark, complemented by a reliable rail around the perimeter. All cabins, including the owner's apartment, are located on the lower deck.

At the customer's choice, their number can vary from three to five. IN in this case we have an average option: four cabins, and the place of a potential fifth one is occupied by a training room. Located in the stern, the master cabin extends almost from side to side (which is 8 m!). Therefore, a monumental bed, an expansive sofa, sections of low cabinets can easily fit here, and there is still so much space left that it is just right for dancing lessons. The dressing room and bathroom also extend from side to side, between the cabin and the engine compartment, and serve as additional sound insulation. However, there is no particular need for this, since behind them there is a double bulkhead filled with sound-absorbing material. The exact same one separates two VIP guest cabins and the crew compartment. For the same purpose, the composite floor of the lower deck is placed on an elastic base.

The VIP cabins have double beds, while another guest cabin on the port side offers separate berths. Naturally, all cabins are equipped with their own bathrooms. There is also plenty of space for water toys on board: the aft garage can accommodate two tenders of 4.2 and 6.5 m in length, as well as a large jet ski; at the same time, there is still plenty of space for all sorts of “little things” like wakeboards, water skis and inflatable “bananas”. It may seem that the most interesting thing about the AB 140 is its design, architectural and interior. In fact, from a technical point of view, the yacht turned out to be no less worthy and even has some relation to Russia in origin.

The yacht's interiors are closer to the classical style than to modern minimalism

During the development of the project, model tests of the hull on a scale of 1:5 took place in St. Petersburg, in the experimental pool of the Central Research Institute named after. acad. A. N. Krylova. During the tests, the main dynamic characteristics of the future vessel were determined, in particular, its behavior on the wave at different courses in relation to the front. The result was a very dynamically stable hull, which did not even require pitch stabilizers. The “sandwich” body is reinforced with Kevlar in especially loaded units to increase strength; its design, as evidenced by the shipyard, provides good sound and vibration insulation, so necessary for a high-speed boat. So good that at a speed of 40 knots the noise level in the cabins is 72 dB, and at a speed of 30 knots it drops to 50 dB.

All AB 140 cabins, including the owner's cabin, are located on the lower deck

So we get to speed - perhaps the main advantage of the AB 140, the achievement of which is subject to a number of design and technical solutions implemented on the yacht. With three MTU engines of 2400 hp. With. (2450 rpm) the boat produces a maximum speed of 40 knots; in cruise mode at a speed of 35 knots, she is able to travel approximately 650 miles without refueling. This is how the hull, engines and water jets work (as we already know, these are the propulsors used as drives on the yacht). Why do we need water jets at all? For speed, maneuverability and reduced draft. The graph, which is present in many textbooks on hydrodynamics, shows that at 50 knots a water jet begins to exceed the efficiency of a conventional propeller, but is still inferior to a supercavitating propeller. At speeds above 80 knots, the water cannon no longer has competitors among serial propulsors. However, each boat has its own characteristics, and it can be assumed that for the AB 140 the second critical speed is lower. But maneuverability with the Swedish MJP 650 water jets, especially when there are three of them, is simply excellent, which is especially important for a large displacement boat.

The smooth profile of the yacht clearly demonstrates its sporting spirit

Now the draft. For comparison, for the 42-meter AB 140 it is the same as for a planing fiberglass boat 15–16 m long with propeller shafts - only within 1.5 m. Many owners of large motor yachts or charter holidaymakers are not interested in what is below the waterline. Although draft to a certain extent affects the quality of rest. The moderate draft allows you to enter secluded shallow bays where you can swim, anchoring almost right off the shore. Usually, large ships have limited choice of such places, and therefore they have much less opportunities to find a secluded anchorage without other yachts and crowds of vacationers on the shore. So a water cannon is a useful thing in many aspects, especially when you learn how to operate it. However, if we return to speed as such, these 40 knots are not the limit at all: the project provides for the installation of three even more powerful MTU engines of 3700 hp each on the AB 140. s., which, according to calculations, should accelerate the yacht to a speed of 53 knots. As far as we know, this option has not yet been built, so someone has the opportunity to distinguish themselves and become the first here.

Moderate draft makes it easy to enter secluded shallow bays

Just don’t ask why SUCH a boat needs SUCH speed. This must be interesting... At 100 km/h on a small cruiser, you are racing, relaxed in the cockpit, gritting your teeth and afraid to raise your head above the windshield, so that a random mosquito along the way does not put a bump on your forehead. On a boat with a displacement of 130 tons, you also fly through the waves at the same speed, but sitting imposingly on the sofa in the cockpit or on the flybridge, and even with a glass of something tasty and healthy... Everything is fine, only the fuel tanks are emptying by more than a ton per hour , and the sea will soon end at this speed - at least ride in circles! But if such boats are being built, it means someone needs it!