Ultrasonic Antifouling

The problem

Every year, biofouling is estimated to add $60-100 billion to commercial shipping costs. This includes increased fuel-consumption, drydocking costs, remedial measures and revenue lost due to regular maintenance and downtime.

On hard surfaces in contact with raw seawater, the biofouling process can start in as little as 15 minutes. It starts with the settlement and build-up of slime and soon progresses to algae, weeds and then molluscs.

When marine fouling grows on the outside of a ship's hull, hydrodynamic drag increases which causes fuel consumption to rise. On the inside of a vessel, marine fouling will reduce cooling water flow and lead to major equipment failure if left unchecked.

On offshore structures like oil rigs and wind turbines, marine fouling will increase weight and hydrodynamic loading. Marine fouling will also account for around 30% of lifecycle corrosion in marine structures.

The science

For decades, ultrasound has been used in the food, brewing and hydroponic farming industries to prevent algal blooms and to keep water-handling equipment clean and free from blockages.

Traditionally, poisons (biocides) have been used to kill organisms that settle on raw seawater surfaces like hulls and box cooler pipework.

Environmental legislation covering the use of poisonous metallic biocides in antifouling systems is tightening and marine-based industries are looking for more effective means of preventing unwanted marine growth on their vessels and inside their equipment

Our technology

Sonihull antifouling systems use the power of ultrasound to protect the inside and outside of marine vessels and structures from unwanted marine growth.

Unlike conventional antifouling coating systems, Sonihull does not release poisonous biocides that kill marine organisms or use ablative coatings that leave microplastic pollution in their wake. Sonihull keeps surfaces clear using ultrasound-induced non-inertial cavitation, which disrupts the biofouling process and actively prevents barnacle and mussel attachment.

Ease of use

The Sonihull Ultrasonic Anti-fouling System is a Fit & Forget solution for hulls, marine structures, box coolers, sea chests, strainers ... wherever there is unwanted bio-fouling.

The Sonihull system prevents marine organisms from colonising solid surfaces that are exposed to raw seawater. Unlike biocidal coatings and impressed-current systems, Sonihull is low cost and low maintenance, with zero poisonous environmental legacy.

Fitting is very easy, there's no need to drydock and drain your box coolers, there's also no drilling, welding, or expensive copper anodes to replace regularly. When compared to impressed-current antifouling systems, the Sonihull system can reduce capital and MRO costs by up to 95%.

Frequently Asked Questions

Will Sonihull’s ultrasonic anti-fouling technology damage the surface?

No. Sonihull will not damage or pit finished surfaces or coatings.

Sonihull uses non-inertial cavitation induced by ultrasound to keep bio-fouling at bay. The process is an established technology, usually associated with cleaning solid surfaces.

Sonihull ultrasonic anti-fouling systems disrupt the formation and proliferation of marine colonies and provide an effective means of preventing mussels and barnacle larvae from attaching to hard surfaces in raw seawater.

The process of ‘non-inertial cavitation’ is similar to ‘inertial cavitation’. The latter is the process that can damage propellers or the insides of pumps. But the forces involved with non-inertial cavitation are much lower. So, with Sonihull, there is no chance of surface damage, like erosion or pitting. That kind of physical damage can only be caused by inertial cavitation.

Does Sonihull’s ultrasonic anti-fouling technology work on all types of material?

The only material that Sonihull does not protect from bio-fouling is wood.

The system relies on internal resonance to transmit the ultrasonic signals to the surface being protected. Compared to man-made materials, wood is full of varying densities and voids and is not an efficient transmitter of ultrasound.

Sonihull provides effective anti-fouling protection for solid materials, including Steel, Stainless Steel, Aluminium, GRP, FRP, Kevlar, Titanium and rigid plastics.

Note - The protection of certain concrete and ferro-cement structures will depend on their individual composition. Silicone-based coatings are known to dampen up to 40% of ultrasonic signals and will reduce system effectiveness. This can be compensated by decreasing the spacing between transducers.

How much power does the Sonihull ultrasonic anti-fouling system consume?

Each Sonihull transducer only consumes 3.6 Watts per hour.

This makes the system ideal for on-board, standby or remote powering options, using 110-240 Volts 50/60Hz AC or 12-30 Volts DC supplies.

Protect your vessel


To deliver effective anti-fouling systems using the power of ultrasound
To save the oceans, one ship at a time