Sonihull | A Comprehensive Marine Antifouling Solution Powered by Ultrasonic Technology
Minimizing Frictional Resistance
High-efficiency, fuel-saving operations powered by ultrasonic technology
Alfa Laval Sonihull uses precision acoustic pulses to prevent marine biofouling before it starts—stopping barnacles and algae on hulls and propellers and mussels inside seawater pipework. By minimizing hull drag, it cuts fuel consumption, improves CII ratings, and significantly reduces dry-dock cleaning and OPEX.
Three decisive reasons the maritime industry chooses Sonihull
Solving operational challenges caused by marine biofouling—from barnacles and algae on hulls and propellers to mussels clogging seawater pipework.
Fuel savings & improved CII rating
Barnacles and algae on hulls and propellers sharply increase drag. Sonihull keeps submerged surfaces clean, cutting fuel consumption by up to 5% on hulls and propellers while maintaining heat-transfer efficiency in onboard cooling systems—directly reducing CO2 emissions and improving your CII rating.
- Stops barnacles and algae from increasing propulsion drag
- Prevents biofouling in engine coolers, maintaining cooling efficiency and saving fuel
- Improves the Carbon Intensity Indicator (CII) score
Longer cleaning intervals and significantly lower maintenance costs
By stopping algal and bacterial biofilm (slime) from forming, Sonihull prevents barnacles and mussels from taking hold—significantly extending intervals between underwater cleaning, propeller polishing, and CIP. It keeps seawater pipework clear of mussels and eliminates costly ICAF/MGPS anode replacements.
- Reduces the costs of underwater cleaning, propeller polishing, and unplanned dry-docking
- Prevents mussels and bivalves from clogging seawater pipes and sea chests
- No consumable anodes to replace, unlike electrolytic antifouling (ICAF)
IMO-compliant and protective of ecosystems
As global port biofouling rules tighten, Sonihull operates with zero biocides, microplastics, or heavy metal discharge. By preventing hulls and sea chests from carrying invasive barnacles, mussels, and algae, it supports compliance in Australia, New Zealand, the US, and beyond—minimizing the risk of port entry denial or fines.
- Zero leaching of chemicals or heavy metals into the water
- Compliant with the IMO Biofouling Guidelines
- Reduced risk of port entry denial and environmental fines due to invasive species fouling
A gentle, long-lasting antifouling mechanism
through non-inertial cavitation
Sonihull transmits pulses at specific ultrasonic frequencies, creating minute pressure fluctuations on the surface of the material. This generates non-inertial cavitation (the formation and collapse of microscopic bubbles), disrupting biofilm—the starting point of biofouling—at an early stage.
Transmission of ultrasonic acoustic pulses
Internally mounted transducers transmit optimized ultrasonic pulses across the entire metal surface.
Prevents biofilm formation
Microscopic surface vibrations stop unicellular organisms and algae from settling. Disrupting this initial biofilm (slime layer) breaks the food chain, preventing barnacle larvae and mussels from attaching.
No impact on base materials or instrumentation
Low-energy pulses operate without shock waves, causing zero erosion or pitting on base materials.
How ultrasonic pulses inhibit biofilm formation on submerged surfaces (video length: 1 min 45 sec)
Three major marine fouling organisms challenging ship operators — protection against barnacles, algae, and mussels
Biofouling is a serious issue that affects not only appearance but also fuel efficiency, operational safety, and maintenance costs.
Sonihull uses ultrasonic pulses to break the fouling cycle of hard marine growth, plant-based slime, and bivalves at its source.
Barnacles
Hard calcareous shells rapidly roughen the hull, sharply increasing drag and raising fuel consumption by up to 40%. On propeller blades, barnacle growth reduces propulsion efficiency and triggers cavitation erosion and vibration.
Disrupts cyprid larvae settlement signals to prevent attachment on hulls and propellers, drastically reducing polishing and diving costs.
Algae & slime
Microalgae and bacteria secrete mucus to form a slime layer. Just 0.5 mm of buildup on heat-exchanger tubes severely degrades heat transfer and risks engine overheating, while creating a foothold for barnacles and mussels.
Microbubble cavitation disrupts algal cell walls and attachment mechanisms, stopping slime formation at the source to maintain peak heat-exchange efficiency.
Mussels & Bivalves (blue mussels, green mussels, etc.)
Planktonic larvae enter through seawater intakes and anchor to grates and pipe walls with byssal threads. Feeding on nutrient-rich seawater flow, they rapidly colonize and block pipes—restricting cooling water and risking main engine shutdown.
Ultrasonic resonance across the pipework stops mussel larvae from settling and maturing, eliminating blockages and manual cleaning.
Comprehensive protection for all seawater-contact surfaces inside and outside the vessel
Flexible protection for every critical seawater-contact surface—from the outer hull to internal cooling pipework and heat exchangers.
Outer hull plating
Stops algae and barnacles from adhering to the hull, reducing hydrodynamic drag and extending antifouling (A/F) paint life while supporting port hull-cleanliness compliance.
Propulsion systems (propellers and thrusters)
Keeps propeller blades and bow thrusters smooth and free of barnacles, maintaining propulsion efficiency, preventing cavitation erosion, and cutting polishing frequency.
Sea chest (seawater intake)
Prevents barnacles and mussels from clogging intake gratings, ensuring steady cooling water flow without the labor and consumable costs of ICAF/MGPS anode replacement.
Coolers and freshwater generators
Stops biofilm formation on box coolers and plate heat exchangers, maintaining heat-transfer efficiency, preventing engine overheating, and reducing chemical CIP frequency.
Strainers & seawater piping systems
Prevents mussels and barnacles from colonizing strainer baskets and pipe bends, stopping flow restrictions and blockages while minimizing manual opening and cleaning.
Seawater tanks and other water-storage compartments
Suppresses algae, slime, and sediment buildup in ballast and seawater tanks, reducing cleaning workload during periodic inspections and extending asset life.
Outstanding performance proven on merchant vessels worldwide
Based on Alfa Laval’s official global field data. In rigorous side-by-side tests under real operating conditions, Sonihull has demonstrated dramatic antifouling effects and improved fuel efficiency.
1,600 TEU container ship:
Maintains twice the cooling performance
Coolers with and without Sonihull were operated side by side on the same vessel for eight months. The treated cooler remained virtually free of biofouling and maintained twice the cooling capacity, achieving a temperature drop of 4°C vs. 2°C.
Ferry in its 10th year of service:
Eliminated overheating at its source
Installed on a ferry suffering repeated unplanned dry-dockings from fouled sea chests and box coolers. Inspection after 18 months showed zero fouling and complete elimination of overheating.
VLCC:
Full investment recovered in just four months
Facing a 1.5% fuel penalty within six months of propeller polishing, the vessel installed Sonihull on the stern tube—extending cleaning intervals, stabilizing fuel efficiency, and achieving full payback in four months.
| Areas Protected | Conventional operation (unprotected / paint only) | After Sonihull installation |
|---|---|---|
| Propellers and propulsion blades | Barnacle and algae buildup increases propulsion resistance, necessitating propeller polishing and underwater cleaning twice a year, as well as costly specialized coatings. | Maintains surface hydrodynamic properties at all times. Prevents barnacle and algae buildup, extending the intervals between cleaning and polishing. |
| Box cooler / heat exchanger | Biofilm buildup caused by algae and bacteria significantly reduces heat transfer. This can lead to main engine overheating and frequent clean-in-place (CIP) chemical cleaning. | Prevents slime and algae from accumulating on heat exchanger tube bundles. Maintains heat exchange performance as designed, while reducing CIP frequency and chemical costs. |
| Sea Chest Grating and Seawater Piping | Barnacles and mussels (bivalves) grow on and block intake grates and pipes, reducing seawater intake. Regular replacement of anodes in electrolytic antifouling systems (ICAF/MGPS) also incurs costs. | Prevents intake grating clogging and pipe blockages to maintain cooling seawater flow. Significantly reduces operating costs with no consumable anodes required. |
Fuel Savings & Payback Simulator
Adjust the sliders with your vessel’s operating profile to estimate annual fuel and CO₂ savings with Sonihull.
Annual fuel savings: approx. 140 tons
Annual CO₂ reduction: Approx. 436 tons
* The fuel reduction rate is a standard estimate based on the official Alfa Laval validation report (1.5%–3.0% improvement in fuel efficiency through propeller and cooler protection).
* CO₂ savings are calculated using the VLSFO emissions factor (3.1144 t-CO₂/t-fuel) specified in the IMO (International Maritime Organization) MEPC guidelines.
* Figures shown are indicative estimates. Contact our marine specialists for a tailored ROI calculation based on your vessel type, trading route, and target equipment.
A product lineup suited to all vessel types
With no through-hull fittings required, Sonihull can be retrofitted in service or during routine port stays.
Scalable modules protect everything from small workboats to VLCCs.
2 transducers
Ideal for the hulls of small- to medium-sized workboats, tugboats and pleasure craft, as well as single coolers
4 transducers
Ideal for protecting propellers, sea chests, and piping on coastal ferries, fishing vessels, and medium-sized merchant ships
6 transducers
For comprehensive protection of multiple systems and the bow and stern of coastal cargo vessels and offshore support vessels
Up to 16 transducers
For large commercial vessels, VLCCs, and container ships. Features 100 m cable length, dynamic thermal control, and automatic restart.
Features of Non-Invasive Installation
Transducers are mounted directly onto the hull or target equipment during dry-docking alongside scheduled inspections and maintenance for maximum efficiency.
Because no holes are drilled in the hull, there is no risk of reduced hull strength or water leaks.
Equipped with marine-grade aluminum/stainless steel rings, universal adapters for piping with a diameter of 35 mm or more, and offset adapters for tight spaces.
Frequently Asked Questions
Answers to common questions when evaluating Sonihull for your fleet.
Regional rapid-response service and 24/7 support connecting major ports worldwide
Keep vessels operating and minimize downtime.
Our service centers across key shipbuilding and shipping hubs and our global network spanning more than 100 countries support your vessel’s reliable operation 24/7, 365 days a year.
Anywhere in the world, 24/7, 365 days a year
Alfa Laval Marine Service
Wherever your vessels operate across any time zone, Alfa Laval Marine Service is on call. Field service engineers (FSEs) stationed at major global ports—including Singapore, Rotterdam, Shanghai, Houston, and Dubai—provide rapid onboard attendance, dry-dock support, and diagnostics.
- Service & Maintenance Support: Expert inspection, diagnostics, and maintenance to keep onboard equipment operating at peak performance
- Global Parts Delivery: Genuine parts and adapters promptly dispatched from distribution centers worldwide to major ports
- Lifetime Support: Comprehensive support throughout the equipment’s lifecycle, from installation on newbuild vessels and retrofits on existing vessels to regular inspections
List of Support Locations in Japan
Directly connected to Japan’s major shipping and shipbuilding clusters. Our dedicated marine engineers based in Japan respond quickly, from design consultations for newbuilds to on-site retrofits for existing vessels.
Meisan Takahama Building 10F, 2-12-23 Konan, Minato-ku, Tokyo 108-0075, Japan
7-11-2 Ichinomiya, Samukawa-cho, Koza-gun, Kanagawa 253-0111, Japan
10-33 Higashi-Onomichi, Onomichi, Hiroshima 722-0051, Japan
2-2-16 Minamifutajima, Wakamatsu-ku, Kitakyushu, Fukuoka 808-0109, Japan
414-1-2 Tanjo, Mihara-ku, Sakai, Osaka 587-0011, Japan
Our specialized technicians provide direct support at every stage, from newbuild construction attendance and dry-dock work to offshore retrofits on existing vessels.
Comprehensive support from Sonihull installation through the entire service life of your equipment
Alfa Laval delivers more than equipment.
From initial assessment and retrofit installation to factory reconditioning and service agreements, we protect your asset value and operational efficiency throughout your vessel’s lifecycle.
Condition assessment and implementation planning
We evaluate your vessel’s operating profile, hull geometry, and onboard equipment to assess biofouling risk and specify the optimal transducer count, placement, and frequency settings.
- Review of the target vessel’s specifications and operating conditions, as well as its hull and onboard equipment
Retrofit Installation & Commissioning Support
Installation is completed in as little as 1–28 days. A field service engineer (FSE) is on hand to ensure proper installation and commissioning.
- Short-duration retrofit during routine port stays
- No hull penetration
- Commissioning
Reconditioning (factory refurbishment)
At our specialized Alfa Laval service centers, we chemically clean fouled coolers, replace gaskets, and perform non-destructive crack testing—restoring design-level heat transfer prior to Sonihull installation.
- Precision cleaning and maintenance at Alfa Laval service centers
- Dye penetrant testing of plates and non-destructive crack inspection
- Restores heat-transfer performance to like-new condition
Service Agreements & Genuine Parts Supply
A maintenance contract that bundles technical support and spare parts supply helps level out maintenance costs.
- Immediate availability of genuine parts
- Custom service contracts
- Global 24/7 Support Access
Related Services and Official Support Resources
Direct access to service information and specialized marine portals on the official Alfa Laval website.