Engine room acoustic insulation: Why is it necessary, what are the benefits & how is it done?

Engine room acoustic insulation: Why is it necessary, what are the benefits & how is it done?

Why should engine rooms be sound insulated on ships, boats and super/mega yachts? What are the benefits and how is it done? What is the best proposed method?

One of the most common complaints coming from yacht owners or charterers is that they can’t enjoy their trip in peace and quiet because of the loud engine room noise.

If the purpose of a vessel is peace and relaxation, noise pollution is the most basic obstacle.

That is why engine room acoustic insulation is of the utmost importance. But let’s explain why the engine room should be sound insulated and what are the benefits offered.

Why insulate a yacht for sound?

All human senses, especially hearing, are based on balance and tension. In absolute silence, the human brain tends towards confusion, while when there is a lot of noise, the body starts to overheat and starts disorganize.

On a yacht, there are many sources of noise. They may come from the interior cabins, the engine room, the propellers or external noises (e.g. from other vessels). More specifically, powerful engines and generators create high levels of noise, regardless of the yacht’s speed. The noises deriving from these two elements, which can be either low or high frequency, are air transmitted thus called airborne noise. That is why the sound absorption of noise caused by the mechanical parts of the yacht is also necessary.

In addition, the engines and generators, when functioning, cause vibrations, either of a small or large range (it depends on the type of engine, speed, possible problems and much more). These vibrations, are known as “structural sounds”, are transmitted throughout the yacht (especially if there is no appropriate dampening), and emitted outside as airborne sounds, that are also perceived as noise.

These sources of noise do not only apply to large commercial or passenger ships. They apply to boats, sailboats, small speedboats, super yachts, mega yachts, cruisers and any type of boat, and acoustic insulation of engine rooms can significantly reduce them.

According to a 2020 survey of commercial vessels, the psychological stress of seafarers comes from vibrations at 80.6% and from noise at 71.8%. That is, heat, which comes third with 45.7%, is not as important in terms of stress as noise and vibrations!

Moreover, studies show that extended exposure to noise above the permissible limit causes nausea, fatigue, muscle tension, insomnia, increased heart rate, and of course, increased blood pressure. If you consider the permissible noise levels ranging from 50 to 70 decibels and the noise pollution caused by the engine room, which can reach from 70 to 110 decibels, you will easily understand the importance of sound insulation. Not solely for the yacht’s structure and engines, but also for the physical and mental health of the crew and passengers.

Key benefits of engine room sound/acoustic insulation

If you own a sailboat or a mega yacht, we advise you to immediately proceed with a sound insulation of the engine room after doing careful research. This is the only way you and everyone travelling with you to enjoy the benefits offered, which are:

Safe hearing

As we mentioned above, the permissible noise limit for humans is between 50 and 70 decibels (dB). The noise in the engine room, however, can exceed 100 dB. This is a very big risk for hearing, from minor permanent problems to complete loss. Especially if the exposure to such noise levels is repeated and of long duration. Another big disadvantage is that hearing is one of the few parts of the body that, if injured, cannot return back to normal.

Stress reduction

What’s the point of going on a yacht trip and not being able to relax with your family or friends? Why should pressure and pulses increase when they should be decreasing? Noises and vibrations, carrying noise as well, cause confusion in our organism.


Increased noise pollution derived from an engine room with no sound insulation, can also cause safety problems. Not just the safety of the yacht ‘s structure, but the safety of the crew as well. For example, if the engine or any other part of the vessel is overheated, no one will be able to hear the heat detector going off since the noise coming from the engine room is quite louder. In addition, constant vibrations can also cause serious damage on a vessel’s structures over time.


A boat needs many types of insulation, such as thermal insulation, duct insulation and waterproof deck systems. Most insulating materials are based on rockwool, polyurethane or aluminum, which are capable at the same time to thermally insulate a boat, keeping it warm in winter and cool in summer, while at the same time provide soundproofing.

Applying Alkyonis’ innovative insulation coating, Mascoat, the quality and performance of sound insulation is drastically increased. This is because the yacht can be thermally insulated and sound-insulated at the same time when coating materials and conventional insulating materials are combined. At Alkyonis we offer integrated solutions for yachts, performing an effective insulation that controls corrosion without affecting yacht’s aesthetics.


A quiet journey is an enjoyable journey. A boat, ship or yacht that does not produce a lot of noise, enables every passenger to enjoy the sea, without extra stress or discomfort. Also, the reduction of the intense noise and vibrations from the machines, protects marine flora and fauna.

How is engine room acoustic insulation achieved?

Engine room acoustic insulation as above mentioned can turn an unpleasant journey into an enjoyable pleasure trip. It is worth noting that a yacht’s acoustic insulation is quite cheaper compared to the costs that may occur from damages due to vibrations.

The best way to reduce overall noise is to insulate the engine room for sound, and more specifically, to minimize the vibrations caused by the engines, which are transmitted through the metal components, throughout the vessel.

At Alkyonis, with over 30 years of experience in the world of insulation, we offer a revolutionary insulation way that of Mascoat Sound Control-dB. It is an innovative way of coating, which insulates sound by minimizing the vibrations caused by the engine room and works in combination with the conventional insulating materials. In this way, the vibrational energy is effectively dissipated and does not manage to turn into noise. That is why it is extremely popular in all types of yachts.

Contact us today for your vessel’s effective insulation and guaranteed result.

Share This Post With Others!

Related Articles