Ultrasonic Anti-Fouling

[nmit5903]

I am giving serious thought to abandoning the annual slip and antifoul in favour of fitting the Boat Sure ultrasonic system.

Welcome any feedback on the system before I commit.

Taking into account the fact that I will still need to slip annually to service the volvo saildrive, the savings really only boil down to the cost and labour (if not DIY) of blasting off and the antifoul itself.

Having said that I do expect to get longer, improved hull performance.

Neil

[Alan Wheeler]

I thought someone may have commented by now. But seems no. So I will give you my thoughts.
Firstly I don't know how this system is really going to effectively work. If it is loud enough to drive away critters, it is going to be loud to everything else in the environment. But besides, the sound is not going to stop weed growth. So if you have one growth, it defeats the entire point in my view. You still have to haul the boat anyway, you still have to clean plant growth, so I se no saving at all.

[Patrick_DeepPlaya]

I'm pretty its not audible to us, it uses ultra (high fequency) sonic (sound) to actually kill the organisms. I could understand this theoretically. I've had ultrasonic therap (very localized deep tissue heat) on my knee and I could see taken to anothe level you could "cook" or kill little tiny critters: Boatsonic: Algae control for boats!

I'd like to see some real users expereinces or have the reseller give you a one year gaurantee with an agreement for marketing, or quotes or something...

-p

[nmit5903]

I have seen the unit in a demo environment and the waves are not perceptible to the human ear - well not mine anyway.

There are a couple of boats in Aust now with them fitted and orders for another coupleof dozen (I believe) - at face value it looks brilliant.

One concern I have seen on some sites is whether the ultrasonic waves could over a prolonger period cause damage to the GRP (eg delamination).

Neil

[GordMay]

I’m unable to find any reliable evidence that Ultrasound is an effective Antifoulant (deterrent/repellant).
Numerous controlled studies have shown that ultrasound is ineffective against mosquitoes, cockroaches, cats, deer, and etc.

Ultrasound is normally defined as sound at frequencies too high to be detected by humans. The upper limit of human hearing is generally around 20,000 Hz, although few adults have effective hearing at frequencies that high.

[nmit5903]

mmmm

There are a couple of sites in the UK that deal with killing of algae in reservoirs using ultrasound. There are a couple of articles by the CSIRO Govt Agency here as well.

I've spoken (in the last couple of days) to two owners here with boats in Newcastle (an hour north of Sydney). The water ranges from 18-21 degrees throughout the year and they are rapped with the results.

The suppliers give a money back guarantee (still have to get it back I suppose) and showed last week at the Sydney Boat Show.

Worst case scenario I ditch $4000 and everyone can learn a lesson.

Best case - it works and I only have to slip once a year + no antifoul.

The long term effects of ultrasound still worry me a bit.

Neil

[Karletto]

the system is not that effective but it will spare u few years more; it is effective more or less against shells etc but not algae; probably 1 transmitter will not be enough for the whole hull; u'll probably have to have 2 or more transmitters, evenly separated, that will cover the whole hull; don't know how the ultra sound from your system will effect your sonar but it could thay'r both ultra sound devices

[Steve Pope]

I imagine it works like an ultrasound parts washer or the type jewelers use for cleaning jewellery. I would have thought that if it was as good as the manufacturers say it would be on every new ship / super yacht / naval vessel etc. Just a thought though what do nuclear submarines use, they can stay out there for a hell of a long time without returning to port. "Oh" of course I forgot, they are still using TBT.

[fstbttms]

Originally Posted by Steve Pope

"Oh" of course I forgot, they are still using TBT.

Not true. U.S. submarines use cuprous oxide-based ant foulings, just like you do.

Underwater Hull - Submarine

[David M]

I hate to break the news, but hull critters ain't got no ears.

[AnchorageGuy]

Niel, What ever the unit cost I can sell you a unit that will do the same thing as theirs, run off 9 volt batteries and I will sell it to you for one half what that unit will cost you.

[David M]

US submarines may as well go out with hydrophones blaring the Star Spangled Banner if they are going to be making ultrasonic noise. Sonar hears these ultra low and ultra high frequencies that we can't.

If something like that actually worked, I think it would have been invented a long time ago.

[GordMay]

Originally Posted by Steve Pope

I imagine it works like an ultrasound parts washer or the type jewelers use for cleaning jewellery...

Do you know how/why an ultrasonic parts/jewelry/denture cleaner work?
Do you think that this mechanism is analogous to (or would translate to) hull anti-fouling applications?

[nmit5903]

Sub's cant use ultraosund - it can be detected - so thats why they have probably stuck with the "medieval" TBT solution.

I put a little ultrasound transducer (get them from any amatuer electrical store) in my sons fish tank. Didnt think it would hurt the fish and thankfully it hasnt so far - its a Fighting Fish and he thinks its a heater - but thats another story.

3 days - algae has died and the weed is in real trouble. "Praise the ultrasound".

Appreciate the feedback and will come back with feedback on the real thing in the next couple of months whilst I evaluate whether I should have spent the dosh on something really useful.

Neil

[Steve Pope]

Sorry Gord I don't know the mechanics of how they work except that they do. My guess is it is through a very high frequency sonic vibration. Any enlightenment appreciated.