CLEAN HULLS, COSt-EFFECTIVE, SUSTAINABLE, INSTALL ONCE.
Ultrasonic Antifouling
Ultrasonic (marine) antifouling works really well because, although it’s a subtle technique, it constantly deals with the easiest, first stage of biofouling on boat surfaces. It’s not trying to scrape hardened barnacles off a boat hull, it’s dealling with the very bottom of the lifecycle of biofouling which you could otherwise wipe with a cloth. Ultrasonic antifouling creates an unpleasant microscopic vibration at a boat’s hull surface (and other underwater surfaces). Water-bourne organisms are physically unable to attach or survive. It’s a proven technique which the US Navy first notice, and now in widespread use on commercial vessel especially. Ultrasonic antifouling is not intended to remove existing hard fouling where barnacles have already settled.
If you want to get into depth about what ultrasonics (ultrasound) is and especially ultrasonic antifouling, read our blog post, Ultrasonic Antifouling ~ Everything You Need to Know, or just ask us.
The Problem

The problem which ultrasonic antifouling solves is to avoid the problem in the first place. Stop this becomming established.
The Solution

Ultrasonic antifouling is a subtle effect to humans, yet an intense vibration in the water that marine organisms can not tolerate and therefore the entire upper lifecycle of biofouling is cut at source.
Ultrasonic antifouling is good for your boat performance & maintenance, your finances, and the environment!
…positive results were achieved with no bottom paint whatsoever… I can see this procedure (system) resulting in minimal fouling or none at all over an extended period of time.
Wally Moran, Cruising World Magazine, Review
There’s a lot of science behind ultrasonic systems, yet they are relatively simple to install Once installed, you can forget about them except for an occasional check they are working.
We hope by the end of reading this page you will be near expert in the installation and function of these systems, and confident to install your own.
The best, and only time, to install an ultrasonic antifouling system is with a clean hull, so make the last lift or dry-dock the last one you will need to perform and without antifouling coatings.
Keeps hulls smooth!
Starting with a clean hull, then an ultrasonic antifouling system will maintain the underwater surfaces in the same condition permanently. It’s not just an annual effect, it’s permanent.
Low power consumption
The control box and transducers work with low power. These systems are compatible with the power from renewable energy such as solar panels and wind turbines found on boats, or also from shore supplies and generators.
Cost effective
These systems costs less than antifoul paint (materials, labour, services included).
Ultrasonic antifouling systems are fitted once, low power consumption, have long life, and are expandable easily if it is found that more effect is required on a certain part of the boat. Indeed, the transducers can also be moved if necessary, (depending on the bonding glue used).
Sustainable
Ultrasonic antifouling involves no biocides to leach into the oceans and marine food chains which we eventually consume.
The constant, permanent smooth hull ensures constant performance and minimal drag.
There are no parts to wear, maintain, or replace in an ultrasonic antifouling system..
A System for Every Size of Boat!
The components are modular and scalable to any size of boat. Select your boat type with corresponding specification from the selection below, or contact us for advice and a customised design.
tugs, ferries, and large yachts
Professional series using 22V to 30V DC onboard, and with harsh environments
Freighters and military vessels
Professional series using 22V to 30V DC onboard, and with harsh environments
Key Aspects
Easy set-up & install
Position the transducers in multiple convenient positions.
No holes in hull
The transducers sit on the inside surface of the hull. No holes are drilled through the hull.
No toxic anti-foul chemicals
There’s simply no biocides required.
Modular
Expand the system components as if required; even relocate the components.
Waterproof & suited to harsh environments
Components are designed for the damp conditions found on boats.
Just Two System Components !
There’s really only two types of component in an ultrasonic antifouling system: control box (power & signals) and transducers (ultrasonic speakers).

One Control box for every 1-4 transducers
A control box powers and sends signals to the transducer. Essentially in terms of music reproduction, the control box is like an amplifier, and the transducer is just like a speaker.
One box can control multiple transducers. Battery or mains power is required to the control box.

One or more Transducers for every 300 m2 area of hull
A transducer creates the ultrasound according to the power and signal from a control box.
Each transducer is connected to one control box. One transducer affects approximately 300 m2 of clear hull which is around 10m radius.
The system is modular and may be expanded e.g. if it is noticed extra ultrasound is required on a part of the hull or surfaces then additional transducers may be used or existing transducers moved (however the glue used to bond the transducer is very strong usually and will need careful attention. It might be easiest to obtain an additional transducer than move an existing one).
Positioning
Take a look at the guidance below and you will probably be able to plan the positioning of the control box and each transducer yourself. We can also easily help you design your system; it’s simpler than you may think. We are happy to take you sketch, layout diagram, photos, videos, or even live video stream to help you.
Control Box(es)
The control box is placed in an convenient location. It’s position has no effect on the ultrasound.
What is convenient? Hidden away for asthetic reasons, close to an easily connected power source, yet accessible in case of troubleshooting, repair, upgrade, or removal. Some control boxes are usually quite tolerant of the wet, humid, hot environments around engines. There are no maintainable parts, and the only access that is generally required is to view the indicator lamps.
Each control box may support more than one transducer. When there are many transducers these might be grouped together with their own independant control box or a larger capacity control box might be used.
See the examples below.
Transducer(s)
The transducer(s) is/ are placed such that the effect covers the entire surfaces to be protected from fouling. On a small boat, just one might be required, on larger boats multiple transducers are required since each transducer is optimised to affect a focussed area of approximately 300 m2 of clear hull which is around 10m radius.
You will have many choices of location on your boat, consider those with the easiest cable routing, access, and position that is out of the way of other functions e.g. storage of equipment & supplies. Once installed, access is unlikely to be required, especially if you can at least observe the indicator light on each transducer and control box to confirm functioning.
It might be less work and easier to install multiple transducers rather than struggle to access awkward locations such as under immovable objects or where the inside surface of the hull is blocked.
See the examples below.
There is no difference between installation on sailing yachts, motor yachts, superyachts, or commercial vessels to be considered except the typical hull shapes e.g. sailing yachts normally have deep keels, whilst motor yachts may have a flatter hull shape and multiple propellers. We are happy to help you design your system, see options below.
The factors to consider when designing your setup are:
- length and shape of hull under water (longer boats require more transducers, multihulls require seperate transducers etc)
- equipment and items e.g. rudders, saildrives, propellers, attached to the hull which might alter or shadow the ultrasonic waves (bias the transducer placement closer to such items)
- structure of the hull i.e. rigid bulkheads may restrict the ultrasonic waves and therefore require transducer placement more biased towards these locations; double-hulls are not suitable unless the external layer can be accessed.
- beam of the boat, as boats get longer they also get wider and therefore more transducers are to cover the width as well as the length of the hull
- internal accessibility and cable routing for each transducer and the control/ signal box and access to power. For an easier install & future access, avoid difficult locations and cable routing.
In the diagrams just here we indicate where each control box (as a blue square) and each transducer (as a green circle) might be installed on boats from 10m to 40m+. When there are more than 1 transducer then installation is usually on opposite sides of the hull staggered along the length. If in doubt, then symetrical spacing is also fine. Generally seek to cover each side and each end of the hull with particular concentration where there may be keels, rudders, and propellers which is why you may notice we position transducers more to the rear in some cases.
Remember, all transducers are fitted inside the hull, not on the outside.
Positioning on Sailing yachts
Here’s some indicative positions for transducers on, say, sailing yachts. A keel can shadow certain parts of the hull, therefore transducers are placed with this in mind.
The key point here is to stagger the position of the transducers along opposite sides of the hull just off the centre-line.
Positioning on Motor boats
Here below are some indicative positions for transducers on, say, motor boats which often have multiple propellers. The considerations are normally the flatter hull shape though there might also be water inlets, sea chests, water coolers to protect too.
Twin screw vessels should preferably use an extra transducer above the aft running gear, as you see in the diagram above.
Get free adviceSuitable Hull Materials
An important note, ultrasonic technology works with almost all homgeneous (uniform density) hull materials. Glass reinforced plastic, steel, and aluminium work well. Therefore, wood is not a suitable material for ultrasonic antifouling since it contains many voids and variable density.
Materials that are dense and uniform permit the sound waves to travel to the outside surface most effectively. The transducer is causing vibration on the surface but when there are multiple voids in the material, the sound is internally reflected and disappated within the material excessively.
This is also why the transducer has to be in firm contact with the inner side of the hull skin. The transducer needs direct affect on the hull surface.
Glass (fibre) re-inforced plastic
Suitable
Steel
Suitable
(but not dual hulls unless access is possible to the outer hull inner surface)
Aluminium
Suitable
(but not dual hulls unless access is possible to the outer hull inner surface)
Wood
Not suitable
Sadly, wood has many micro and macroscopic holes which do not allow the ultrasound to travel effectively.
Concrete/ Cement
Not suitable
Sadly, concrete/ cement has many micro and macroscopic holes which do not allow the ultrasound to travel effectively.
We're Here to Help You
System installation is normally very simple, and certainly after your own installation, you will likely agree. However, we are here for you at anytime, for questions regarding devices, installation, specifications, options, issues, concerns, or just a chat.
Especially in these socially safer times, you can chat to us on WhatsApp by voice or video, send us video or photos of your boat, plans, and discuss the ideal selection of items, positioning, installation, and maintenance now and in the future.
WhatsApp Video conference
+44 (0)7593 415 984
Walk & talk us through your boat or location, at a mutually pre-agreed date & time
WhatsApp us
+44 (0)7593 415 984
Quick question, or photos/ videos to share? Just send us a WhatsApp message anytime.
Email us
hello@dreamsails.co
Send us any message, video, drawings, photos.
Frequently Asked Questions
Are Fish affected?
No. They are happy to carry on swimming around the hull.
Does our system affect Echo Sounders?
No. Both work on different frequencies.
Why do we bond transducers direct to hull?
To transmit maximum power to the hull and stop transducers coming loose through vibration. Screw fixes can work themselves free.
What is the power consumption?
That depends on the system size. Full specifications are available on the system information pages.
The power consumed is low. For example, one system uses just 3W per transducer on 12V DC & 24V DC inputs.
Can I make my own transducer cables?
Yes. The signal cable is quite simple. For example: some systems use RG6 satellite cable with plated brass F-type cable connectors. Especially, although we can supply 5m and 10m long cables on larger vessels these will not be long enough.
What is maximum transducer cable length?
We now have new driver technique to allow up to 60m using RG6 cable.
Do I have to replace a fuse if there’s a fault?
No. We use electronic fuses in both inlet and transducer drive circuits. They will automatically reset after fault removed.
Can you use our system to protect sea chests?
Yes no problem. Ask for further information. We can help with special adapters and placement of transducers.
Do you have system for commercial vessels?
Yes. There are systems for leisure/ pleasure craft as well as commercial vessels of all sizes. Some systems have even been designed for miltary users and tested to a higher temperature & vibration range.
Do I have to Dry Dock My Ship to Install the System?
No. Antifouling systems can be fitted whilst the vessel is afloat. There’s usually no cutting or penetrations required. All the components are fitted on the dry side of the hull, coolers or pipework.
Is It Environmentally Friendly?
Yes. 100%. No pollutants are deposited into the marine eco system. Even some packaging is eco-friendly.
What’s the return on investment?
Normally fantastic, and it doesn’t pollute our planet like biocides and other antifouling coatings do. The return can be just one or two seasons, or less. Compare the cost of current antifouling paints which requires lifting the boat, removing old coatings, sanding, applying multiple layers of new coatings & sanding, the labour & services employed, loss of use of the vessel, and that such coatings immediately start to degrade.
Once installed with a clean hull, an ultrasonic antifouling system provides continuous protection year after year at low power and therefore optimum boat performance without lifting the boat.
Motor vessels, and commercial shipping will obtain significant benefit on vessel journey time, down-time for maintenance, and fuel saved.
Do ultrasonics adversely affect marine mammals?
No. The waves are not at a frequency or pressure that adversely affects e.g. whales and dolphins.
Can I fit the system myself?
Yes. Many customers do their own install. We provide full instructions. Larger vessels the ships engineer is normally happy to install.
Will Antifouling Work on My Vessel?
Ultrasonic antifouling will work on any solid metal or composite hull, pipe or component. It does not work on wooden hulls. If your vessel has a foam or wood cored GRP sandwich construction, then a section of the inner skin and core needs to be removed and the gap built up with solid GRP to enable the transducer to emit ultrasonic waves to the outer shell.
Do I Still Need to Use Antifouling Paint If I Fit Ultrasonic Antifouling?
No not for antifouling. The ultrasonics are doing the antifouling. However, you may still need to protect the hull with a suitable inert, protective coating for impact resistance and asthetic reasons. Ultrasonic Antifouling doesn’t protect against metallic corrosion or GRP osmosis.
Do I need Antifouling paint?
Generally not at all. Some hulls last longer with anti fouling paint so please check this out.
How Do Ultrasonics work?
Check our detailed fabulous blog post, linked here: Ultrasonic Antifouling ~ Everything You Need To Know
WHAT OTHER OPTIONS DO I HAVE TO DEAL WITH MARINE FOULING?
Take a look at our article Antifouling Options
Antifouling including ultrasonics Antifouling options