Boat Engine Soundproofing: How to Reduce Noise & Vibrations
Anyone who has tried cruising on a boat to relax will understand the appeal. However, others who may have not gone boating may prefer to laze around in the beach and think that it is all the same. However, being by the ocean is not the same is being on it.

There are just so many benefits of boating like deep fishing, being able to do aqua sports like paragliding or water skiing, relaxing with a wine glass while enjoying the gentle lull of the ocean, and so much more. However, as any boating aficionado will know, there is one down side to boating and that is the noise. The boat engine is just loud on an earth-shattering and core-shaking level.
If you truly want to enjoy this boating experience, you’re going to have to find ways to mitigate this sound. Otherwise, the noise is just too distracting and it takes away from the experience. Every boat owner should be aware of how to minimize the noise because it does wonders in helping the passengers relax and really enjoy the activity.
In this article, we will talk about how to soundproof your boat engine. We will give you a list of materials you need, the reasons why you need to soundproof, and a step-by-step guide on what must be done to dampen the sound of your boat engine. Read on below and let’s gets started.
Materials You will Need








If you are afraid to embark on this project, worry not because even amateurs will be able to accomplish this project with ease. Thankfully, products are now easily accessible online in Amazon, so you can have these delivered right to your doorstep. The best part about using a reputable site like Amazon is you are given competitive prices that will not compromise your pocket.
Your boat engine sound dampening project will need the following:
- Foam for insulation for the high frequency sounds
- Roadkill Damping Material Bulk Pack for broad spectrum sounds
- Mercury Motor Cover for a customized fit
- Rubber insulation mats are essential for soundproofing
- Take out your trusty tape measure for best results
Why Should You Soundproof Your Boat Engine
First, let’s go over the critical part of why you should soundproof your boat engine. The noise your boat emanates overshadows the benefits of boating which are reducing stress, anxiety, and other mild ailments by providing a therapeutic remedy along with the fresh sea air. On top of that, boating strengthens your mind as you have to think on your feet and memorize nautical terms as you steer your ship.
In addition to that, boating is a social enterprise that allows you to engage with many different kinds of people, even your loved ones. Unfortunately, all of these perks are negated when your boat engine noise is just too darn loud. Here’s a rundown on how these loud sounds and noisy vibrations can be harmful for your health and well being:
- A boat’s engine is capable of producing decibel levels above 110. This is a very scary and dangerous level that bears with it a serious risk. You can actually acquire hearing damage over a period of time.
- Vibrations with a super high intensity are capable of degrading your bones and muscle structures, which can lead to serious physical ailments. Thought this may not be common, there is still a possibility of this danger, so you have to make the necessary precautions so you won’t fall into this kind of harrowing scenario.
- When your boat engine is too high, your risk of injury is also high. They are directly proportional to each other. When the engine is so loud, the risk for miscommunication with the people on board is high. You can take a nasty slip, steer in the wrong direction, and the like because you cannot hear your mates warnings.
As you can see, it is really critical to soundproof your boat engine. Apart from making it hard to have conversations with your guests on board, it carries with it serious health issues that can potentially harm you. As a responsible boater, you must never compromise yourself and your passengers, so soundproofing your engine is a necessity.
How To Soundproof Your Boat Engine
Now, let us move onto the more important aspect of how to reduce the noise coming for your boat engine so that you cope with its annoying sound. In this way, you will be able to fully enjoy your boating experience and embrace all its wonderful benefits.
Be aware that you can never fully take away all the noise. However, you can reduce it to acceptable and tolerable levels that do not hurt your eardrums. There are generally two ways to go on about this projects, which you can do easily by preparing your materials and buying them from Amazon ahead of time.
The first method is to soundproof the outboard motors and the the other is to soundproof on the inboard motors. Let us tackle each one, separately. Take note of the various steps involved in each process by reading below:
1. How to Soundproof the Outboard Motors
Most engines do have a covering but it usually does very little in covering the excessive noise. This type of covering is called a cowling. It is, however, very ineffective and inefficient unless you decide to supplement or top it up with something far better.

When you’re working with the cowling, you have to keep in mind that this contraption is a part of the engine. Treat it lightly, with care and caution. Generally speaking, this is not a delicate piece of material, but you don’t want to be haphazard and inadvertently cause damage to it.
The material this piece is made with may may make it more susceptible to malfunctioning. Read your manual thoroughly so you can check the make of this material because it will determine if it sturdy and brittle.
Now, take a look at what you can do to mitigate the sound from the cowling. You can install insulation on this cover and on the insulation material attached to it as well. This may seem redundant to do it twice, but by doing this you can soundproof better and mitigate noise more efficiently.
Foam and insulate
Foam acoustic padding will be very useful, but take note that it only eliminates high frequency sounds. For best results, it is best to use something like this Roadkill Damping Material Bulk Pack, which is touted for eliminating sounds from both ends of the spectrum because it is dense and flexible enough to do so.
For best results, you have to shop around in your favorite hardware store or in Amazon so you can find what best suits your needs. You may even meet or chat with an expert who can give you advice. Remember, there’s no shame in asking for help and they value customers that know how to ask for help.
Ensure that sound dampening materials fit and there are no obstructions
The next step is to make sure to fit the material as much as you can with the inner cowling. You have to ascertain that no air vents are blocked and your additional padding will not touch any moving parts. Doing so can have detrimental effects to your boat’s engine.
If you obstruct the air ventilation system, it can lead to overheating. It will also demote the integrity of the motor. What’s worst, this is actually a safety hazard that may result in a nasty accident.
The same holds true if your sound dampening materials touch any moving portions. Moving parts create friction, so any form of obstruction can lead to a catastrophic ending. In worst case scenarios, this can even cause total engine failure.
Constantly check the air flow as you go about with your soundproofing project. Be vigilant in ensuring that there is no obstruction anywhere to avoid all sorts of issues.
Double check to see if you need more soundproofing
You may need to cover the surface area of the cowling itself if you think that more sound dampening is needed. The first two steps will reduce some noise, but the more effort you put, the more the sound is masked.
- Provides outstanding protection for an engine during transit or in storage
- Black cover features bold white Mercury branding in multiple locations
Using something like a Mercury Motor Cover is a great idea because they can be customized to fit your boat engine. Be cautious about slippage because this can cause your engine to overwork and overheat. If you feel as if it doesn’t look right, then make the necessary adjustments.
2. Soundproofing the Inboard Motors
In general, inboard motors are easier to deal with because they are pre-insulated. You can opt to add some rubber insulation mats from Amazon for best results. Make sure not too be excessive and not to be too stingy either. Balance is the key to success
You have to ensure that you buy jus the right amount. It is a common mistake to underestimate or overestimate. Some buy a lot or to little, which is a fairly common error. Even if it is tiresome, you have to measure the area that you’re covering precisely with your your favorite tape measure or you have to use the manual, at least, as a reference, is the best approach.
- Proudly made in the USA with global Materials in new Britain, CT.
- 11 feet of standout* for extra reach when working alone
If you veer towards the extremes, there is a possibility that you will overheat the parts, and that is the last thing you want to happen. Keep in mind that any breaks in the insulation or any unbalanced application will prove to be detrimental.
The key to application is to be patient and to go slow for the best possible results. To make sure that everything is in proper order, take your newly insulated motor on a test-run. By maneuvering it on the actual waters, you will get a good idea if you efforts worked well or not.
Remember not to scrimp on this part because taking risks will end in a disaster. It is vital to proceed with caution and to double check if everything works to a tee. Take it slow on your first test run, so you can really check and quickly address any potential issues.
Last Word on Soundproofing Your Boat Engine
The engine noise may seem not like a big deal to experienced boaters, but this may be due to the fact that they have inadvertent ear damage that they are unaware of. It is critical to address a noisy boat engine because it can be detrimental to your health and it may cause untoward accidents.
As you can see, with just the right sound dampening materials on Amazon, you can easily address the problem. By doing these steps, you can certainly make the very best out of your boating experience without busting your eardrums. With a quieter engine, you can enjoy cruising the waters to the fullest without having to worry about the downsides of a loud motor.