Does Ultrasonic Antifouling Work?

I would want to see them tested 30 years or so before I'd be tempted. Otherwise we have no idea the long term effects, do we?

Seriously, I'm not big on new concepts until they are proven through extensive actual use. For some things, that's 6 months. For others, it's years.

+1 ... I agree 100%

Must be interesting trying to raise a tuna with that thing banging away....

These things don´t even work well for the dealers. The snake oil business is hard theses days...

I found it at FLIBS yesterday. Ultra-Sonitec distributes them in US (this product was developed by Globatech in Australia). It is worth visiting them at FLIBS, the sales person is able to explain the technology, he had pictures of growth with/without in the same boat at the same time; allegedly they installed a transducer at one end and let the other end unprotected.

Based on the representative, it is capable of slowing barnacle and weed growth. This is also what the photos show. Installation is relatively simple, transducers are glued to the interior side of the hull and connected to a control unit.

The cost of a unit with four transducers and installation materials is $1995. Four transducers are required for boats between 30 and 45’.

He presented an impressive list of customers, including the USCG.

A friend just returned from FLIBS and asked me about ultrasonic anti-fouling systems. I don't have any experience with these systems. A few years has passed since this thread was posted. Wondering if any of our readers have used them?

I see a couple of products still out there. Hull Shield seems to target smaller boats and Sonihull targets larger and primarily commercial ships. Sonihull seems to be building some solid relationships such as one with Konsberg. They even have mounted transducers in the housing of jet drives to clean the jet drives.

I'm impressed by what Sonihull is doing, even though not to the point of being practical for most of us yet. Also, impressed that they recognize limitations and here are pros and cons they show on their website, which I think are pretty objective:

Pros​

• • Sonihull’s ultrasonic technology provides proven effective protection against marine biofouling including algae, weeds, mussels and barnacles.

Cons​

• • Ultrasound is an effective anti-fouling solution in niche surfaces like pipework systems, box coolers, propellers and bulbous bows. Retrofitting to protect full hulls on larger vessels may be hindered by bulkheads and tankage, so General Arrangement Drawings will need to be reviewed by our Naval Architect. This does not affect new build vessels.
  • Ultrasound is unlikely to remove the need for some kind of hard coating on the hull.

On shafts and props they offer this:

Pros​

• • Fits easily on the dry side of the stern arrangement without the need to drydock
  • Protects clean propellers continuously without any drop in performance
  • Ultrasound frequencies used are safe on all types of lube oil and grease.
  • Works 24/7, even works when a vessel is idle in port.
  • Very low MRO costs and quick ROI.

Cons​

• • Requires careful consideration of the General Arrangement drawings to ensure predictable propagation of the ultrasound waves.
  • High initial capital outlay, which is recouped very quickly by reduced fuel consumption and prop-cleaning schedules.

There seems to be an even easier application for piping of large ships and for sea chests.

I found their case studies interesting at sonihull.com. I see the potential for full hull protection but at tremendous cost and limited benefit. However, I see the special applications use strong and can easily see them as an alternative to props or jet drives for high speed boats. I also see the benefit to commercial ships where any downtime is costly. Seems to me that even with their success stories, they're still figuring it all out, figuring out the best applications and how to use their technology. The determination of where and how to install and the proper angles seems to be quite complex. I would likely consider for the jet drives or for shafts and props before hull.

I did find the one testimonial from a recreational boat interesting as it's a 65' steel trawler kept at Brunswick Landing Marina. He did report good results. Of course they didn't publish testimonials from those who didn't. I believe they are still at the point where all are not working out as hoped initially so some are requiring more work or changes. I see it as a technology with a future but still being refined.

I also looked back at Hull Shield and they seem to moderate their claims to the extent they don't claim no need for bottom paint nor that you won't still need some cleaning, just say less frequently. Oh and they do indicate that it's a little easier with metal boats than composite or cored as you may need to remove some of the layers to install. I'm assuming this is something to do with thickness and material. So, they don't claim it as a cure all but as an aide.

I found a third system, Ultrasonic. Very similar system. I found it interesting they added a PowerPlus or higher power system. To me, an indication the initial system isn't enough power. Here a more definitive point on hulls. The maximum thickness is 70mm. Also all three make it clear the systems will not work on wood. The reason is that it requires a solid substrate to resonate throughout rather than one with joins like wood.

They also make the point that on a double hull or a cored boat, you'd need to remove a bit of the inner core to mount the unit as it must be in contact with the outer hull. They talk about continuing your anti-fouling paint but may only have to do so every 3 to 4 years.

So, I think not a cure all but potentially a good tool. I do think placement and use is some science and some art as the science is still being developed. It's worth continuing to follow the progress.

Oh dont waste your money just keep up the normal maintence of a boat, just like a house you have to always paint it and maintan it .

happy boating