Many anglers and waterwalkers who first saw a flat vessel with a huge fan on the stern on the river, ask themselves, what is the name of a boat with a propeller in the back? Unlike conventional boats, where the thrust is created by an underwater propeller, this design uses an air jet. air-brusherAlthough in everyday life you can often hear the terms "airboat" or "aircraft-propeller boat".
Their operation is fundamentally different from traditional motorboats, which are not created in water but in the air, allowing them to speed at high speeds even in shallow grassy waters or wetlands, and it is this unique ability that has made them indispensable in remote regions of Siberia and the Far East.
In this article, we will examine the structure of these machines, find out why they are called that way, and consider the key differences from classic outboard motors. You will learn who will suit such a vehicle and what are the nuances of its operation in real conditions.
Official terminology and origin of the name
Technically competent name of the boat, propelled by a propeller, - air-brusherThe term is derived from the Greek root "aero" (air) and the French "glisseur" (sliding). However, to be precise, aircushion boats are often referred to as aircushion vessels, although in the context of propeller boats, this name has taken root as a synonym for aircraft.
In the professional environment of boaters, the term is also used. airboat These boats are common in the United States, especially in Florida, where they are used to patrol marshy areas, and Russia has historically developed its own school of building such vessels, often referred to simply as "airboats" or "propeller boats."
It's important to understand the difference between an aeroglissor and a hovercraft (CVVC). A classic propeller boat on the back doesn't have a skirt that pumps air under the bottom to get off the water. It moves through the water, dissecting it with its hull, like a regular PVC boat or an aluminum boat, but it's pushed by an air jet.
- 🚤 Aeroglisser The general name for a water-sliding vessel with an air propulsion system.
- 🌬️ Erboat (Airboat) The international name, often used by equipment manufacturers.
- 🔧 Air propulsion - the technical name of the node that creates thrust.
The name “back-boat” is descriptive and does not carry technical load, but it is most often found in search queries of users who are just familiar with this type of water transport.
Air propeller design and arrangement
The main thing that distinguishes this boat from any other is propellerIt's located in a safety ring at the stern of the boat, and it's powered by a propeller mounted on a special frame. Unlike underwater propellers, which work in dense water environments, the propeller has to be much larger in diameter to capture enough less dense air.
A protective ring, or jacketIt's a critical safety feature that prevents the blades from coming into contact with foreign objects, branches, or, worst of all, people on board or in the water next to the boat, and the propeller can rotate at several thousand revolutions per minute, so having a secure fencing is a must.
The engine is usually mounted high above the deck, and most often powerful motors (e.g. from VAZ, GAZ or foreign cars) adapted for operation on water are used, and the torque is transmitted to the propeller via a belt or chain gear, which allows you to change the gear ratio depending on the task.
⚠️ Attention: The operation of a boat with an unprotected propeller is strictly prohibited! the absence of a casing poses a mortal danger to passengers, especially during sharp maneuvers or the roll of the vessel.
The thrust control is not by turning the screw itself, as in outboard motors, but by using special air rudders, these metal plates are located directly behind the screw in the air flow, when the steering wheel turns, the air flow is deflected, and the stern of the boat is carried in the opposite direction.
Why do the screws make wooden or composite?
Metal propellers for airships are rarely used, as they are heavier and more dangerous when broken. Wood and composite materials (carbon fiberglass) have the necessary strength, lightness and when hit by an obstacle, they will split rather than turn into fragments-bullets.
Advantages over screw motors
Why would someone choose a noisy, bulky structure with a propeller in the back when there are quiet, compact outboard motors? The answer lies in the operating environment. passabilityHe's not afraid of a depth of 10 to 15 centimeters.
Where a conventional propeller instantly winds up algae, grass or silt, the propeller won't even notice the obstacle, making them the perfect tool for fishing in the deltas of reed-covered rivers or for hunting in swampy terrain, and you don't have to worry about the expensive lower unit of the motor.
Also, the lack of protruding parts under water reduces the resistance of the hull and allows you to develop high speeds in shallow water. Also worth noting is the ease of maintenance: the engine is at the top, it is easy to reach for repairs or oil changes without pulling the boat out of the water.
But there's a downside to the coin: Aeroglisser is much noisier than its screw counterparts, the roar of the motor and the whistle of the screw can be heard from several kilometers away, and for a fisherman who values peace and quiet, it can be a serious drawback, scaring fish and annoying others.
Comparative table: Aeroglisser vs Outboard motor
To make a final decision, you should compare the main specifications of both types of propulsion, which will help you to understand which option is suitable for your tasks.
| Characterization | Aeroglisser (Propeller at the rear) | Outboard motor (screw in the water) |
|---|---|---|
| Permeability | High (up to 5-10 cm depth) | Low (risk of damage to the screw) |
| Noise level | Very tall. | Medium/Low (with silencer) |
| Fuel consumption | High (powerful motors) | Medium/Low |
| Management | Harder at high speeds | Excellent, accurate. |
| Safety of the screw | Covered with a casing. | Open, dangerous for swimmers |
As you can see from the table, the choices are based on priorities. The aeroglider has no competitorsIf you want to be more efficient, quiet and maneuverable in deep water, you'd better stay in the classics.
Features of management and maneuvering
Control of a propeller boat requires certain skills and habituation. Unlike classic boats, there is no "neutral" in the usual sense - the engine either runs on idles or pulls. Braking is only done by dropping gas or turning the air rudders, which is not always effective at high speed.
The rotations are made by the deflection of the rudders. At low speeds, the boat can be sluggish because the airflow is weak. The efficiency of the rudders increases dramatically with increasing engine speed. This creates a paradox: to get to the shore slowly and carefully, you need to master the gas.
- 🔄 Inertia: A propeller boat has a lot of inertia and cannot stop instantly.
- 🌊 Wind impact: Due to the high sailing (the engine and the screw stick up), such boats are strongly demolished by the lateral wind.
- 🛑 Reverse: Reversing the aeroglisser is difficult and rare; usually the boat is simply turned around.
Experienced drivers use gas steering to maneuver accurately; short power flashes allow for rapid retracement; beginners are advised to first practice in open water away from obstacles to experience the inertia of the vessel.
Safety and operating rules
Safety on the water is priority number one. A boat with a propeller at the back is a source of increased danger. Rotating blades create an invisible but deadly barrier. So having a strong safety fence around the propeller is not just a recommendation, it's the law.
All passengers must be provided with life jackets, and in the event of a rollover or fall overboard, the risk of being hit by a working propeller (if the engine has not been silenced) or being injured by structural elements is very high, and the noise of the engine can drown out the cries for help.
⚠️ Attention: Before starting the engine, make sure that there are no people, animals or light objects in the range of the air jet (cone by boat) that the wind can lift.
Regular maintenance is also a safety measure, including checking the engine mounting, the condition of the belts or transmission chains, and the integrity of the propeller blades, and cracking the blades at high speeds can cause them to fly apart and the protective casing to collapse.
☑️ Checking before getting on the water
FAQ: Frequently asked questions
Can I make a boat with a propeller myself?
Yes, many enthusiasts build such boats themselves using engines from Oka, VAZ or Izh motorcycles, but this requires a deep knowledge of mechanics and welding, as well as strict adherence to safety measures in the manufacture of a protective casing.
What is the maximum speed of an aeroglisser?
Sports models can reach speeds of up to 100-120 km / h or more. Civil and fishing versions usually go at a speed of 40-60 km / h, which is enough to move on a reservoir.
Do I need to have the right to operate such a boat?
In Russia, to control a small vessel with an engine capacity of more than 8 kW (about 10 hp) requires the rights of category "M" (motor boat) and registration of the vessel in the GIMS, if its weight with an engine exceeds 200 kg.
Why don't you put a screw in the water when it's so big?
A large diameter is required to capture air that is 800 times lighter than water, and if you put a screw like this into the water, the resistance is enormous, the engine can't spin it, and the efficiency drops to zero, and you need small screws with a large pitch for water.
Is that boat making a lot of noise?
Yes, the noise level is much higher than that of an outboard motor, due to the lack of a water muffler (water extinguishes exhaust sound well) and the aerodynamic noise from the propeller, and the use of noise-canceling headphones is common practice for the driver.