Marine biofouling is a challenge as old as seafaring itself. From small skiffs and fishing boats to superyachts, the accumulation of bio-organisms on submerged surfaces leads to performance degradation, structural risks, and a significant increase in operating costs. 

Studies show that even light slime layers can increase fuel consumption by up to 15%, while heavy fouling can cause drag increases of more than 40%. Particularly in planing boats with multiple large engines, the increased fuel costs can be enormous.

The degradation in performance is also a factor, reducing cruising speeds and restricting range.

Traditional anti-fouling paints have long been the standard defense, but they release copper and biocides into marine ecosystems, posing regulatory, ecological, and maintenance challenges. The BPS Marine Pro Series ultrasonic anti-fouling system represents a modern, non-toxic alternative that leverages physics rather than chemistry to combat fouling.

Understanding Biofouling

Biofouling develops in stages, each of which impacts vessel performance. Here, more or less, is the process that eventually winds up making your hull ugly, inefficient and slow:

1. Microfouling (Biofilm Formation)
   Within hours of immersion, a conditioning film of proteins and organic molecules forms on the hull. This film provides a foothold for bacteria and algae spores, creating the first layer of biofilm.
2. Algae Growth and Slime Layers
   Algae and diatoms colonize the biofilm, producing slippery slime. This slime coat looks bad but is not the primary problem in fouling. However, it creates a surface on which macro-fouling critters—barnacles, mussels, tube worms and others—can attach to and thrive.
3. Macro-fouling (Barnacles, Mussels, and Tube Worms)
   Larvae of barnacles, mussels, and other invertebrates settle on the prepared surface. Once attached, they grow rapidly and can form dense colonies that are difficult to remove without abrasive cleaning.

These organisms make the once-slick surface of the bottom rough, crenulated and ugly. Left untreated, these organisms not only increase fuel consumption and emissions but can also damage coatings, block water intakes, and accelerate corrosion on metal parts.

The Science of Ultrasonic Anti-Fouling

The BPS Marine Pro Series disrupts this biological succession using ultrasonic transducer technology. The system employs a network of transducers bonded to the interior of the hull, which transmit ultrasonic signals (typically in the 20–200 kHz frequency range) through the vessel’s structure and into the surrounding water boundary layer. It’s available in both 12- and 24-volt versions.

The ultrasonic mechanism works in three primary ways:

1. Acoustic Microstreaming
   High-frequency vibrations create localized micro-currents at the hull-water interface. These disrupt the initial biofilm formation and prevent algal spores from attaching securely.
2. Cavitation Effect at Microscopic Scale
   While not the violent cavitation seen in propellers, the controlled micro-bubbles induced by ultrasonic energy destabilize algal cells and fungal spores, reducing colonization potential.
3. Larval Deterrence
   Barnacle and mussel larvae are reportedly highly sensitive to vibrational and acoustic environments. The ultrasonic pressure gradients interfere with their settlement behavior, discouraging them from attaching to the surface, per researchers.

These effects occur at the microscopic level in the water boundary layer to prevent fouling from initiating, rather than attempting to remove growth after it occurs.

Multiple Advantages Cut Costs and Down Time

• Continuous Protection – The system operates 24/7, even while moored, ensuring that fouling doesn’t gain a foothold.
• Non-Toxic – Unlike copper-based paints, ultrasonic waves don’t release harmful substances into the environment.
• Reduced Maintenance – With less hull cleaning and fewer haul-outs, yacht owners save time and cost across the vessel’s lifecycle.
• Fuel Efficiency – A consistently clean hull translates to optimal performance, reducing fuel burn and emissions, increasing available speed and range.
• Hull and Coating Preservation – By eliminating harsh scraping and chemical cleaning, coatings and hull materials last longer.

Bottom line is, in many applications, the ultrasonic system can actually pay for itself not only in terms of better performance and hull appearance, but in actual cash savings on fuel and maintenance.

Regulatory and Environmental Context

With global regulations increasingly restricting the use of copper and biocidal anti-fouling coatings, yacht owners are being forced to seek alternatives. The International Maritime Organization (IMO) and regional authorities are tightening controls, particularly in sensitive marine areas.

The BPS Marine Pro Series avoids the issue of noxious bottom paints entirely by offering a compliant, environmentally sustainable solution. 

Per the company, a 50’ (15.24m) twin-engine cruiser installation can pay for itself in just 8 months of recreational use, and unlike anti-fouling coatings, does not have to be re-applied every couple of years and does not require down-time for re-application.

The system can add value and utility to any vessel stored in the water, and is particularly useful in warmer coastal areas where marine growth takes hold fastest.