Fitting UltraSonic Antifouling

April 12th 2013

After having issues with weed growth on the hull spoiling some of our breaks to the boat I have decided that anti fouling alone is insufficient for our particular needs in the Med.

Checking out Utra Sonic Anti Fouling on forums etc provided a whole host of subjective comments from a lot of people who have never actually fitted any of the products available on the market. Not a lot of help really!!

I therefore decided to conduct my own due diligence; and after separating the wheat from the chaff I decided to go with the product designed and manufactured by Ultra Sonic Anti Fouling I selected this company as they were very helpful and informative; plus it was patently obvious they were not simply trying to get an order but were answering my questions honestly and openly (as opposed to some others !!) and they offered a 3 year warranty.

The process is simply to abrade back the paint and rough fibre glass until there is a smooth flat surface…….no doubt this will be easier on a new boat but on an old ruggedly built boat like Sun Dog this took a bit of doing due to a rough finish on the inside of the hull. Boy is fibre glass tough material!…….so out went the plan of a sanding block with 80 grit paper, and out came the wallet for the purchase of a sanding machine !!

This is a photo of the starboard forward unit – I had used tape to hold the flange in place while the epoxy cured for 24 hours. Once you have a smooth flat surface, you simply epoxy the flange to the hull and into which the transponder will screw…….as a safeguard I used Vaseline to coat the threads to avoid any potential issues should any epoxy manage to get into them.


Forward unit with the transponder screwed in and cable connected.

Similar was done in the port side aft and, after everything was completed, a coat of paint finished the job.

The cables from each of these transponders run back to the control unit which I fitted in the aft bulkhead of the engine compartment.

There are a couple of observations I would make about this particular kit. There are two cables supplied one 8 metres long and the other 4 metres long and these have plugs already fitted which means a 20mm hole needs to be drilled to enable the cable and plug to pass through any holes. However, and this is worthy of note, one end of the cable has a male plug while the other end had a female one..…….worth double checking before you run the cable in and find you have run it back to front as this would definately spoil your day!!

(Update: 16/4/13) In speaking with this company upon my return they have taken note of the above and will be making mention of the need to ensure the cable is run correctly within their manuals etc – excellent response and full credit to them for being so pro-active.

Rather than use silicone or sikaflex to fill the holes does anyone know of some kind of “bodge” material that is suitable to fill the holes but will not permanently seal the cables in – but will go firm enough to stop cable chaffing or water ingress?

On Sun Dog (35ft) the 8 metre cable was just long enough, while the 4 metre cable was too long and I had to double it back on itself as you will see in the photo of the aft fitting.

I also wasn’t totally happy with the security of the control unit fitting onto the backing plate as it seemed (to me) likely to come off in rough seas therefore I put some tape across the top for added security.

Later this year I will have the boat lifted as I couldn’t get a lifting slot this week at the club. For the moment I have left the Ultra Sonic kit running 24 hours a day, as the solar panels will keep the batteries charged. The company say that the product is not meant as a means of getting rid of existing fouling and cleaning the bottom of the boat, however they do say that a difference should be seen after a period of six weeks has elapsed. I will let you know……….

May 25th 2013

The ultra sonic anti fouling package we fitted uses 1.1amps of power, therefore 26 amps per day. The solar panels we currently have fitted are 2 x 30w (therefore max 60watt/12v = 5amps) requiring about 6/7 hours of sunshine to maintain the batteries and cover this level of power draw. Therefore when we left the boat we didn’t leave her connected to shore power as we thought the solar panels would provide sufficient charge. This turned out not to be the case as Barcelona had not been getting sunny weather, therefore the batteries were low when we arrived back at the boat – so in future she will be left connected to shore power and the “smart” battery charger will do the rest. To be fair it would probably have been fine if we had been using the boat regularly.

At the club we managed to get a slot to have the boat lifted out the water and pressure cleaned the underside to remove all growth and slime. There is no doubt that the underside of the hull was a whole lot cleaner than it would have been prior to fitting the ultrasonic kit. This will now afford us the opportunity of fully and finally assessing the effectiveness of this piece of equipment and remove any doubt/ambiguity as we are re-starting the evaluation with a clean underside. However I think its fair to say that this system, without doubt, offers boat owners a major contribution to maintaining a clean hull.

When the boat was painted at the beginning of 2012; Peter from Paradocks Painting used a French product called Velox on the propeller, and I have to say that when the boat was lifted I was blown away by how clean the prop was – the Velox coating was intact and still doing it’s job. Pete stated that as long as the instructions are followed to the letter the results are always the same – top product.

So that’s it until the next time the boat is lifted out the water – very encouraging.

August 29th 2013

Since having the hull cleaned (but not re anti-fouled) and re-launched back in May I have been keen to revisit and see how effective the Ultra Sonic kit has been working. I’m delighted to say that we are just back from Barcelona and I am pleased with the cleanliness of the hull as can be seen from the pontoon – such a difference to the situation prior to me fitting this piece of kit.

Nothing can be 100% perfect and there is some barnacle (?) growth that can be seen through the water and a bit of slime but virtually no weed growth is visible. Based on this three month spell I am convinced that the investment is proving to have been worthwhile. Final verification will be when “Sun Dog” is next lifted out the water later this year/early 2014 and we can see the extent of fouling and also if there are any parts of the hull isolated from the effects of the ultrasonic.

It’s fair to say that I was a wee bit sceptical of ultrasonic antifouling at the outset, but given the results so far on a hull based in Barcelona (warm water) I am more than a happy bunny.

One clear and tangible bonus that the system works, is that in moving the boat this time, the bowthruster tube was sufficiently clear and thus worked perfectly – now that did put a smile on my face – as previously it has been blocked with weed growth. This is normally a pain in the rump given the limited manoeuvring space my current berth affords.

Even though we were chuffed at this working so well, I did have reservations about running this ultra sonic antifouling system 24/7/365, but when I called the company I was reassured by Nick Griffin that their system can be left running with no detrimental effects to the hull. He directed me to the testimonials page on his web site which I found extremely comforting, especially the testimonial from Miss Behave a Beneteau 50 based in Hong Kong.

Check out this and all the other testimonials – as they do back up my own findings thus far.

January 9th 2014

When the boat was lifted out for survey I was pleased to note that there was virtually no weed at all on the underside, but there was a fair degree of barnacle (?) type growths on the hull as can be seen in the following photos. Now my initial reaction was one of disappointment, but to be fair there are a number of factors still to be taken in consideration before I make final judgement on the effectiveness of this piece of kit.


(1) The boat is sitting in a deep harbour and not moving very much at the moment, therefore rendering the anti fouling on the hull a wee bit ineffective as there is no water regularly flowing over the hull. Remember also in the Med there is not much tidal flow compared to the UK!

(2) The underside wasn’t coated with fresh anti fouling when last lifted and cleaned in May 2013. Sun Dog was last antifouled in January 2012.

(3) Now I don’t know for sure if this next point is valid, but I have had issues with battery power, and cutting a long story short, I discovered on this trip that the domestic bank of batteries are no longer holding a charge, and therefore perhaps the Ultra Sonic kit has not been delivering its full effect, as it cuts out when the voltage drops to save draining the battery completely.

August 17th 2014

Well its now over seven months since Sun Dog was lifted out the water, had the underside cleaned and new antifouling applied. This was to enable the final “objective test” on the efficacy of the Ultra Sonic Antifouling fitted originally fitted in April 2013. See previous posts on this under categories.

Sun Dog has just been lifted out with the bottom completely clear of growth, the only thing on the underside was a coating of slime which washed off easily.

These photos show the boat as she was lifted untouched out of the water….not even rinsed off!

Starboard Side

Port Side

I am now both absolutely convinced and impressed with this product, and the underside of the boat is really clean despite the best efforts of the Mediterranean. I am also delighted that the bow thruster tube that used to foul up really badly (and stop the thruster being effective) is also clean and the thruster is working beautifully. On a long keel boat this is a real boon when allocated a tight berth in a marina.

I would also make the following observations to aid anyone considering fitting this equipment to their boat.

(1) Mistake I made at the outset was not having cleaned and antifouled the hull before fitting, because if I had then this evaluation would have confirmed its benefits to me sooner.

(2) With us fitting the two transponder system the current draw I plan for is around 1 amp and our small solar panels were simply not sufficient enough. Consideration should therefore be given to strong enough solar panel/wind generators. If the boat is kept in a marina connected to shore power and has a battery charger connected, then obviously there are no issues.

(3) We have left this kit running 24/7 but perhaps the manufacturers could integrate (for those on a swinging mooring or at anchor) some kind of timer so that in the hours of darkness the unit could be switched off – thus reducing overall 24 hour power draw. Might also be relevant for yachts on long passages…….

(4) With the hull being clean the boat sails much better through less drag, and when it comes to power boats I would assume there would be a noticeable increase in speed against revs, coupled with a noticeable reduction in fuel costs.

So to all those who have been asking me about this product I can now say with confidence that I am totally convinced on its effectiveness – subject to the above quantifications/observations.

For the sake of clarity: I have no association with the company or any of its agent and the above comments (and those of previous posts on Ultra Sonic Antifouling) are purely my personal observations and experience.

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