Ultrasonic antifouling

... Jon Mendez is both a tried and trusted contributor to MBY as well as a Sea School owner with first hand experience of fouling in the Solent. True, he doesn't have a full set of photos showing the precise level of fouling from previous years but if he says that last year he lost a couple of knots off the top speed of his school boat due to fouling on the sterngear but this year with USAF fitted he only lost half a knot, I'm inclined to believe him.

That's a bit of a cheap shot Hugo, neither I nor jfm ever questioned Jon's integrity, in fact I specifically made the point that I didn't. I just said that fouling varies from year to year, so it wasn't a good test.
 
I suppose if they were scientists they wouldn't be writing for a magazine, so maybe they need some help in defining a meaningful test? As a minimum we need an unpainted hull with ultrasonic, an unpainted hull with no ultrasonic, and a hull painted with conventional antifoul, all moored in the same place. If the product worked it would be of immense interest to boaters, so worth the cost of a test like this.

MBM has not tested these products. I have been trying to get a test organised for over a year now but have been unable to come up with what I believe to be a scientific enough set of circumstances to give the sort of result that I, as a boater, would want to see. I have the offer of the kit and am being regularly chased by the supplier to get a test organised, so they are obviously confident of their product.

I agree entirely with Nick H above, but also have to concur with Hugo that getting these boats is almost impossible. There is also the added problem that if one boat moves, the others should also, and should move at the same time, the same speed and for the same distance to the same locations. This is going to be impossible, so you come back to having three static boats. Now where can I get three boats in the same place that are not going to be used for the whole of the summer?

In fact I would go one further than Nick and say you also need a boat painted with A/F and also fitted with U/S.

Now I could combine the unpainted hull with no U/S with a painted boat with no U/S by doing half and half on the same boat, but that still leave a requirement for 3 boats.

I am open to offers or suggestions as I would love to see the results of such a test as much as you guys.
 
Apologies if I phrased that badly, I was just trying to make the point that although we don't have perfect scientific proof, Jon is a very reliable source. As a number of people have now pointed out it's almost impossible to arrange the ideal test, so either we do nothing at all and nobody is any the wiser or we do the best we can in the circumstances and follow it up as and when better opportunities arise. Hopefully JFM will be able to provide valuable extra insight this season and I'd urge anyone else who is having it fitted to send me a pm as well. The more feedback we can get from people with different boats in different locations, the more we can build up a body of evidence that should provide a wider consensus on how effective it is or isn't.
 
Yeh, that'll be interesting. My boat is moored right next to jfm, similar size and type of sterngear, similar cruising speeds, and we may well end up with similar hours, so the next best thing to two identical boats, one with USAF, and one without. Both hulls will be freshly antifouled, so it wont tell us anything about hull fouling, but should be quite a good test of sterngear fouling in Med conditions. I'll try to schedule my lift about the same time as jfm, then take under water photos of both sets of sterngear before I do my first prop scrub around the start of June.
 
A true test is going to be virility impossible to carry out without a large budget.
The only test for me is fitting the units and seeing if it works for me on my boat with my usage.. Been running for a week now, but only time will tell how good it is.
 
MBM has not tested these products. I have been trying to get a test organised for over a year now but have been unable to come up with what I believe to be a scientific enough set of circumstances to give the sort of result that I, as a boater, would want to see. I have the offer of the kit and am being regularly chased by the supplier to get a test organised, so they are obviously confident of their product.

I agree entirely with Nick H above, but also have to concur with Hugo that getting these boats is almost impossible. There is also the added problem that if one boat moves, the others should also, and should move at the same time, the same speed and for the same distance to the same locations. This is going to be impossible, so you come back to having three static boats. Now where can I get three boats in the same place that are not going to be used for the whole of the summer?

In fact I would go one further than Nick and say you also need a boat painted with A/F and also fitted with U/S.

Now I could combine the unpainted hull with no U/S with a painted boat with no U/S by doing half and half on the same boat, but that still leave a requirement for 3 boats.

I am open to offers or suggestions as I would love to see the results of such a test as much as you guys.

Yup, that all makes good sense. I'm happy to play ball as much as feasible. At the moment my plan is to have an ultra 20 system (already bought) installed at same time as my next lift out (in a month). Both vibrators above the props, becuase M66 paint does a perfect job on the hull and I only care about the metalwork. After a season I will have good photos of (a)sterngear with no coating, (b)sterngear with propspeed, (c)sterngear with no coating but USAF protection. All on the same boat (well, 2 different Sq58s) and the same berth and similar use each year. I've already put on here the pics for (a) and (b)

But none of this will provide any info on the effectiveness of usaf on the hull. M66 paint is so good that any lack of fouling can be all attributed to the paint, and says nothing of usaf's effectiveness. So, if it would help, at my imminent lift out I can paint a 50cm square of hull with (say) black gloss paint to in effect remove the antifoul paint. Just as was done on Motala. Then we'll have an extra comparison of usaf with a/f paint and usaf without it, to add to Jon's Motala data.

Also Nick if you were to use M66 paint this year that would make us able to compare better in a year's time

If anyone has any further suggestions I'd be happy to implement them
 
If you're happy to paint a black square of neutral paint as a control panel that would certainly add an extra dimension to the test. We could then explain the plans for the test and give on-going updates in the Our Boats section of MBY and follow it up with the full test results in Tried and Tested at the end of the season. Please make sure that it is installed properly (and preferably approved by USAF) so that there is no debate about this after the event. Would you like to me to talk to them to see if I can arrange this?

Also if anybody else decides to have this or another system fitted please get in touch with me so that we can include other smaller case studies from around the UK/Med.

Many thanks

Hugo
 
Please make sure that it is installed properly

Ahem, I was going to :-). And will photo it.

(and preferably approved by USAF) so that there is no debate about this after the event. Would you like to me to talk to them to see if I can arrange this?

Feel free to. They'd have to schlepp down to Antibes but that's fine; there's someone on the boat every day. While you're talking to them ask them to answer the "Why Knot" conundrum on the other thread :-)
 
From my point of view, it isnt the fouling on the hull that the U/S needs to fix - its the fouling to the stern gear thats important - even the cheapest antifull does a good job at keeping the fouling under control on the hull.

IMO, testing squares on the hull isnt tackling the root problem - its the props, rudders and shafts etc that needs to be protected and U/S doesnt do anything for them - IMO of course.

I'm going to us M66 this year but I really think that U/S is a complete waste of time.

As I've said before, the new Sunseeker in the next berth to me had equally as much growth and had a professionally installed (and then checked) U/S system installed. A complete waste of time and money.

Interestingly, it seems to me that the fouling in our marina is a lot less this season than last - I'll see in a couple of weeks when we lift.
 
From my point of view, it isnt the fouling on the hull that the U/S needs to fix - its the fouling to the stern gear thats important - even the cheapest antifull does a good job at keeping the fouling under control on the hull.

IMO, testing squares on the hull isnt tackling the root problem - its the props, rudders and shafts etc that needs to be protected and U/S doesnt do anything for them - IMO of course.

I agree mike, and my test will be specifically on the sterngear. Becuase, like you, that's all I care about in view of the facct M66 paint gives near-perfection on the hull. As you know I have photos of the sterngear bare, and with propspeed, so usaf will be the 3rd and final comparison.

Both my USAF vibrators will be installed directly above the props

My proposal to have a square of hull with no M66 paint is just a useful and valid add-on to the test, but doesn't diminish its core objective of finding a cure to the sterngear problem.
 
From my understanding these things work by emitting U/S through the hull, so I would have thought that they are unlikely to work very well on props and shafts which are somewhat insulated from the hull with rubber bearings. Will be interesting though.
 
From my understanding these things work by emitting U/S through the hull, so I would have thought that they are unlikely to work very well on props and shafts which are somewhat insulated from the hull with rubber bearings. Will be interesting though.

Depends on the power of the transducers. With the units I have fitted there should be an area of about 5 meters around the boat covered. It will be interesting to see the effect on the boat next door and the pontoon.
In a lake application an area of 150 x 150 m can be covered. In the future it may also be possible to cover all the boats in a marina by placing transducers round the edge of the marina.
Food for thought?
 
One more thought JFM. Do you know if the bottom section of your hull is cored with foam or balsa and are USAF confident their system will work on your boat regardless? There seems to be some debate about whether this extra layer of stiffening acts as an insulator to ultrasonic waves and reduces the efficiency of ultrasonic systems. This is the reason Blue Green turned down our request to fit their system to our Beneteau Monte Carlo 37 last season.
 
From my understanding these things work by emitting U/S through the hull, so I would have thought that they are unlikely to work very well on props and shafts which are somewhat insulated from the hull with rubber bearings. Will be interesting though.

Well if it doesn't work on the props and shafts then it's a real chocolate teapot, given that USAF have already conceded that it doesn't negate the need for antifoul paint on the hull.
 
From my understanding these things work by emitting U/S through the hull, so I would have thought that they are unlikely to work very well on props and shafts which are somewhat insulated from the hull with rubber bearings. Will be interesting though.

Agree with NickH. If these things don't work on sterngear then they are consigned to the dustbin of history as far as I'm concerned along with Propspeed and Velox Plus. If they are just an alternative to antifoul paint, forget it. I have been trying to get some kind of comment on sterngear fouling from the supplier on this post but no comment. Maybe I know why now
 
One more thought JFM. Do you know if the bottom section of your hull is cored with foam or balsa

No, my hull isn't cored.

I can well imagine it wont work on a cored hull. The vibrator is meant to make the hull panel vibrate, so transmitting the US waves to the water. In a cored hull only the inner GRP layup would vibrate, not the outer, so it wouldn't work
 
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