Anti antifoul

by Adrian on August 18, 2013

One of our more unusual tech investments (they’re all investments, not gadgets!) recently has been an electronic ultrasonic anti-foul system.

Ultrasonic Box ShotThese systems promise to keep your hull clean and free from marine growth – thus reducing friction, improving sailing performance and maintaining fuel efficiency when motoring.

More importantly (for us) this also removes the requirement to haul the boat out of the water every year to repaint the bottom with new anti-foul paint.

Traditionally, keeping the hull clean relies on this noxious paint inhibiting barnacles and weed from attaching itself to the bottom of the boat by providing a slippery, slightly caustic and self-depleting surface. This is also not very environmentally friendly as by definition anti-foul has to be hazardous to marine life.

Since it works by slowly wearing itself away, anti-foul needs to be replaced each year and this represents a sizeable annual cost.

New Antifoul appliedThis year we spent over £1000 for a haul out, storage ashore, paint, materials and labour.

The technology

Ultrasonic anti-foul systems use technology borrowed from industrial cleaning systems to dislodge bacteria and microscopic marine life from the hull before it can establish itself by literally blasting it off with bursts of high frequency (ultrasonic) sound waves minutely vibrating the hull.

Aluminium is a dense material, so is particularly suited to this type of system. Its too early to tell, but we hope to be able to get away with antifouling only once every 3 or 4 years. We still need an anti-foul layer, but have been able to choose a much harder and less erosive compound (Seajet Emperor 034 – black).

The options

There are a number of ultrasonic anti-foul systems on the market, all costing roughly similar amounts, so after a lot of research and discussions, we chose the product from a relatively new British company called Ultrasonic Works.

Ultrasonic Works

These guys really know their stuff. They’ve produced a second generation product that not only does a good job but really enhances the usability of the system through well thought out additional features and attention to detail:

  • Their transducers (which fire out the ultrasonic waves) have the voltage transformers built into them. This means the cables running through the boat only carry 12v (not the 800+ volts as in other systems) which seems to make sense.
  • The system is expandable and can take up to 4 transducers as standard.
  • The control unit has a decent 4 line display with which you can monitor the system’s status, see exactly how much power is being used and configure a wide range of operational parameters.
  • The system has built in movement sensors which can automatically turn the system down or off when sailing or dried out.
  • The kit comes with a mains adaptor and 12v connections, so it can be set to provide 100% power (about 1 amp @12v) when on shore power (ie in marinas) and reduced power consumption (500-750mAh) when on 12v (at anchor). All these parameters are user configurable.
  • The system can also detect ambient temperature, and thus boost power and modify the frequencies used for tropical water or warmer areas.
  • A sim card slot and mobile interface is standard, which allows system performance and power information to be automatically sent to head office by SMS – so they and you can monitor and even modify the system’s configuration and performance remotely.
  • The ultrasonic frequencies used are automatically varied and cycled to maximise effectiveness and minimise power usage. Their guys at R&D are constantly evolving the most effective sound patterns to disturb and inhibit different types of marine growth, so any new findings can be automatically pushed to your system via SMS.


The kit is easily installed and there is a well written user guide and manual to help. (The company also offers fixed price installation if you don’t want to bother routing wires around your bilges yourself).

Installation involves simply bonding (glueing) the transducers to the inside of the hull at strategic locations and running each control cable back to the control unit. Good quality waterproof connectors are used throughout. No holes have to be drilled in the hull or anything else modified. The installation kit generously comes with everything you need, including gloves, epoxy, wet & dry paper, foam rings to contain the epoxy whilst runny and drying and tie wraps and cabe tidies to make a neat job.

Ultrasonic Contents

You can buy a system with one, two, three or four transducers depending on the size of your vessel. We’ve installed three transducers to incorporate sufficient coverage for our lifting keel and twin rudders, but on most <45′ boats, two are sufficient. Each transducer is effective for approximately 10m2 of underwater area.

The control box mounts easily and needs either 12v or 240v supplies (or ideally both). If you want remote monitoring and control, simply slot in a cheap pay-as-you-go SIM and add a bit of credit for occasional SMS messages. If abroad, the sim functionality can easily be disabled or set to report less frequently.

In use

Power it up and after a self check and initialisation process the system just works. Each transducer is pulsed in turn to keep power usage to a minimum, whilst the display tells you exactly how much power is being used and what frequencies are being utilised.

We are aware of a very faint and irregular clicking sound in the hull – a bit like the noise you get at anchor when bubbles from the seabed hit the hull.

This might be annoying to those who are particularly sensitive, but we’ve quickly grown used to it and don’t notice it any more. If you wish, you can reduce the sound by insulating the transducers by covering them with towels or foam sheet – or even program them to reduce power at certain times.

Does it work?

Its a bit early to tell – we hope so. We didn’t have any growth when we dried out last, but it had only been 3 months since our haul out. A winter in Brighton will tell.

The future

From what we’ve heard, the warm Caribbean waters and lush mineral rich island estuaries are particularly prevalent breeding grounds for marine growth – with hand scrub downs needed after just a few weeks at anchor. We hope this system will reduce the need for both this and annual haul outs. Hopefully we’ll be able just to dry out and touch up any areas that need attention and just change the anodes.

The company

Ultrasonicworks don’t seem to be a company to rest on their laurels. They are busy with small yacht installations, motorboat installations and even commercial installations on large tankers incorporating hundreds of transducers.

They exhibit at all the major boat shows and I’d recommend you having a talk with them.

Future developments include the possibility of using ultrasonics to keep your water in your boat tanks fresh and clean by zapping any bacteria before it grows, and even more interestingly, using ultrasonics to keep diesel free from diesel bug microbes before they grow, expand, die and sink to form the dangerous filter-blocking sludge.

The company is also looking at expanding the communications abilities of their control box to allow remote monitoring of other external systems, such as bilge alarms, movement detectors, security switches, GPS etc.

{ 6 comments… read them below or add one }

Chris May 17, 2015 at 05:55

HI guys, thanks for the great blog. Glad to hear your journey is going well. I just thought I would let you know that after many attempts to contact Ultrasonic Works they have just replied to me to advise they are “no longer dealing with the leisure market”. Thanks anyway guys. Enjoy.
Tayana 48


Adrian May 17, 2015 at 06:00

Thanks Chris. That’s a shame. I knew they were having a hard time selling the volumes they needed to make a go of it. It’s obviously a tough business. I’ll change my posts to reflect this.


Chris May 17, 2015 at 06:12

No probs Adrian, I wanted to use their system purely based on your review here. You do a great service with all your research and it is much appreciated. As you said though, it must be a pretty tough market. From what I have seen the ultrasonic antifouling does have a place on a leisure boat. Cheers and safe sailing.


Kat February 25, 2015 at 17:46

We ordered this system for our boat (still in build) on your recommendation! How about an update – it’s been about 18 months now. We’re really curious as to how it’s working now that you’re in warmer waters.


Adrian March 4, 2015 at 04:26

Kat, I’ve just posted an update with some comparison pictures and my thoughts a year and a half on. Thanks for getting in touch.


pc April 19, 2014 at 02:16

really glad I found your website. i’m very interested in Allures and all of the modifications you’ve made. was wondering if you had any update on the ultra-sonic antifouling system? was it worth it?

thanks again,


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