A More Eco-Friendly Alternative To Traditional Antifouling

Published: 11/04/13 at 09:31am

We all want our boats looking and performing at the absolute best. We’ve all seen this, a beautiful yacht with a dirty hull. It can be a real eye sore and have a dramatic impact on your fuel economy and performance. This is why you have to constantly haul your boat out and scrape the hull clean and reapply antifouling paint. You know what, you don’t have to throw your money away with frequent haul outs and hull cleaning. Having a Sonihull ultrasonic antifouling system combined with a good antifouling paint will greatly extend the periods between haul outs, thus saving you money.

How Does This Sonihull System Work?

Sonihull ultrasonic antifouling system works by destroying single cell organisms such as algae, thus eliminating the barnacles and other marine life food source. This is achieved through a process known as cavitation.

What is cavitation? According to Princeton, "Inertial cavitation is the process where a void or bubble in a liquid rapidly collapses, producing a shock wave… Noninertial cavitation is the process in which a bubble in a fluid is forced to oscillate in size or shape due to some form of energy input."

So what does all this mean? The ultrasonic transducer in the Sonihull system pulsates in various frequencies producing shock waves. There are two parts to this shock wave, high and low pressure. During the low pressure phase bubbles are formed, and during the high pressure phase these bubbles are compressed and implode. This is what kills the single cell organisms such as algae that barnacles and other marine life love to eat. By removing this part of the food chain you eliminate the possibility of fouling on your hull.

Will This System Harm Fish?

Numerous tests have been done, and all results show that there is no danger to fish. No chemicals or metals are released into the open waters with the Sonihull system. The only thing that will be killed are organisms such as algae.

Save on Fuel and Maximize Your Performance

Any fouling on your boat will lead to increased resistance, which hurts your fuel economy. A clean hull can save you up to 30% on your fuel bill. Do the math and find out what 30% of your annual fuel bill is, that’s a lot of dough!

A yacht journal did some sea trials to determine how much of an increase in fuel economy after using the Sonihull system. They measured the performance before and after spring lift of a 10 year old Princess 430, that has been equipped with twin Volvo TAMD63P engines that are rated at 370hp at 2800 rpm. Below is a chart showing the comparison before and after. You can clearly see an increase in mpg once the Sonihull system was installed.

MPG chart before and after Sonihull system

Sonihull or Oceonic?

There two ultrasonic systems available, the Sonihull and the Oceonic. The Sonihull provides antifouling to hull of the boat. While the Oceonic provides antifouling to the sea chest, inlets, filters, valve seats and pipe work. Each system has two models offered, one with a single transducer another with two transducers.

It Still Involves Teamwork

It is still advised that you have some type of antifouling paint on your hull in combination with a Sonihull system.

There have been reports of residue or slime when using the Sonihull system, this is simply dead algae. A simple swipe with a hand or brush will remove this from your hull. Even water running along the hulls surface will remove this.

Remember, the Sonihull system will NOT remove barnacles already growing on the hull. It is meant as a preventative measure combined with antifouling paint.

Transducer and stern drive adapter

What About My Stern & SailDrive?

What’s nice with the Sonihull system is that there is an optional stern / SailDrive adapter. A ultrasonic transducer is simple screwed onto the adapter, and the adapter is bolted onto the stern or SailDrive directly.

Have any questions or comments on the Sonihull ultrasonic antifouling system? Go ahead and contact us, email us at or call us at 425-355-3669.