Bow Thruster Noise Issues and Methods to Minimize It

The Thruster system may have been making noise ever since it was installed or over a period of time. If you are someone who pays attention to external sounds while sailing, these sounds can be quite annoying. Even if you are not bothered by it, the thruster system may disturb your crew or boat occupants because it is installed very close to living spaces. So, do we have to live with this noise? There are a few ways to reduce bow thruster noise or prevent it from occurring in the first place.


Minimizing Vibration and Noise Caused by the Body During Installation

The noise problem of the bow thruster is largely influenced by the hull of the boat. The reason is that every boat hull produces an echo in a certain frequency range. This echo can result in the thruster sound being either louder or quieter. This phenomenon is known as structure-borne noise.
To reduce this type of sound, the thruster system should be installed in a position that minimizes the vibration and sound emanating from the hull. Additionally, you can choose a thruster system that can absorb sound and vibration, which will help reduce the overall sound level.

Reducing Cavitation

Cavitation is a phenomenon that occurs when vapour bubbles form in water and then suddenly collapse, causing damage to nearby materials. To prevent cavitation, it is advisable to choose the largest tunnel diameter that is suitable for your boat. This can increase the efficiency of your thruster and provide more space for water thrust, thereby reducing noise. In addition, the quality of polyester and assembly workmanship are crucial factors in reducing cavitation. Expertly smoothing the area where the tunnel meets the hull helps minimize cavitation and turbulence caused by the propellers.
Using Low-Noise Propellers

If your system has suitable hardware, you may want to consider using the low-noise Q-prop propeller, which is a new type of propeller. Traditional 4-bladed propellers have a gap between their blades that results in noise and cavitation whenever water hits the transmission. However, the new 5-bladed propellers eliminate this gap and prevent cavitation issues. Although the manufacturer claims that it can reduce sound by up to 75%, it is more reasonable to expect a reduction of 20-40%. Moreover, some thruster models have been reported to experience an increase in power with the use of this propeller.


Switching to Pro (PPC – Proportional Power Controller) Speed Control

Variable speed control allows for the application of cleaner power by gradually applying force to the thruster system. By utilizing a powerful thruster system and the PPC system at a low power level, a sound frequency that is almost undetectable to the human ear can be achieved.

To switch to the PPC system, you will need a PPC control unit and an upgrade kit. You can seek assistance from our company for professional help in determining whether your system is compatible and for any issues related to the conversion kit and labour.