Sonihull ultrasonic antifouling - does it work?

Ianqv

Ianqv

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Hi All,

Does anyone out there have any experience of Sonihull (http://www.nrgmarine.com/).
It sends out an ultrasonic signal via a transducer/s which are fitted to the inside of the hull - and this is meant to keep your hull free of weed and barnacles!

I was just wondering if it does exactly what it says it does??

Many thanks

Ian
 
I guess the answer is no. YM is I believe publishing the results of a trial this Autumn of this type of system and I am sure we will all be interested in the answer.
 
Well the boat is in Scotland atm, so it might not be revealed for a while yet

If you do go for US antifoul, don't forget you need a means of powering it, so you'll need to find a source that can provide around 1 amp/hour 24 hours a day 365 days a year.

Easy when you're in a marina, but budget in £150 for a metered lead if your marina requires one. Some do some don't.

If you're long term cruising the constant power consumption is something you should seriously think about
 
snooks said:
Well the boat is in Scotland atm, so it might not be revealed for a while yet

If you do go for US antifoul, don't forget you need a means of powering it, so you'll need to find a source that can provide around 1 amp/hour 24 hours a day 365 days a year.

Easy when you're in a marina, but budget in £150 for a metered lead if your marina requires one. Some do some don't.

If you're long term cruising the constant power consumption is something you should seriously think about
Click to expand...

Sorry Graham, but I struggle to understand your numbers. This depends on the system you have installed, the length of the boat, the number of transducers etc.

I have the system from blue green marine and it has been running continuously for 18 months or so. Great results.

We are aubot 45ft, 4 transducers and consume 3 amp hours per day. No problem with a medium sized solar panel.
 
I have had a system fitted, there is a lot of information in the MOBO forum regarding it.
So far it works for me but there are a number of systems available and there is a lot more to it than "just fit ultrasonics" Its down to the power and type of transducer, the material the transducer is made from and the position they are fitted in. Also another key point is the length and frequency range of the waves.
I know the system I have works for me, When I last lifted together with other boats mine was by far the cleanest and totally barnacle free.
 
SolentBoy said:
Sorry Graham, but I struggle to understand your numbers. This depends on the system you have installed, the length of the boat, the number of transducers etc.

I have the system from blue green marine and it has been running continuously for 18 months or so. Great results.

We are aubot 45ft, 4 transducers and consume 3 amp hours per day. No problem with a medium sized solar panel.
Click to expand...

According to Blue and Green the current drawn by their system is 0.6A
Link here
PBO came to an average of 0.3A for a single transducer system

Ultrasonic's power consumption was measured by PBO to be around 0.8A for each transducer, Ultrasonic say around 0.7A
Link here

So while it's on, I have to find around 0.8 amps because I have one Ultrasonic transducer fitted to Pixie

The system is on 24 hours a day, for 365 days a year (or whenever your yacht is in the water). So I have to provide power for it all the time, as well as top up the batteries when my source of power stop generating, when there is no wind for example, and the antifoul has run the batteries down.

In a marina that is fine, it's plugged into shore power (Well it would have been fine if the supply hadn't tripped and the wind gen was off, nearly flattened the batteries)

But while I was off cruising for extended periods, having a constant drain on my batteries, was a something else to worry about, especially when our alternator packed up.

Put simply, solar panels only work 50% of the time (i.e. when it's not dark), and rarely do they achieve their maximum output, unless they are completely unobstructed and angled towards the sun. During our 3 months in Scotland we had a handful of days when the sun was out all day and therefore would have been providing enough power for a solar panel to work at it's claimed output. I would (in very basic theory) need a panel that would provide at least double the power consumption of the US antifoul if every day was sunny). Even then there is no guarantee that the panel would provide enough power for the antifoul without running down the ships batteries.

Your figure of 3 amps per day seems very low and equates to 0.125Ah however using Blue and Greens figures you should be consuming 14.4 amps at 0.6A or 7.2 at 0.3A over a 24 hour period, both are more than your findings

I have to find 19.2 amps to power my US antifouling. My battery capacity is 220ah, and for the longevity of the batteries their charge should not go below 50%, so I have to find roughly 1/5 of my usable capacity every day.

This was why anyone considering US antifouling also has to budget for how they are going to power it.
 
NRG Marine Sonihull Duo

My brother had a Duo on his beneteau oceanis 37. Its moored in Dubai and i went out to help fit it. It was quite straight forward. He has shore power so there wasn't an issue with battery drain. He has used it running from the batteries and there was no problem. The NRG unit had a battery guard which will shut itself off if the batteries go down to 11V.
After nearly 2 years in the water the hull is still clean.
If i ever plucked up the courage to invest in a boat, i would defiantly invest in one.
 
My brother has a boat in Dubai. I helped him fit an NRG Marine Sonihull Duo. Basically 1 control box and 2 transducers. It was fairly easy. The beauty of the Sonihull is that the control box has a battery guard which turns itself off if the batteries drop to 11V. But this has not happened to him yet.
The boat has been in the water for 2 years now and is clean as a whistle. He recommends these to his friends. If i take the plunge and invest in a boat, i would defiantly look to install a Sonihull.
 
I guess I'm going to jump into this discussion also. I live in South Florida and have had a unit for the past year. I had a friend convince me about putting one in my boat. He had good results with his in NY. My boat is a 36ft. Seahawk with twin diesels. I just had the bottom painted before it was installed. I used an ablative bottom paint. I was sceptical about the whole process because as an Electrical Engineer I would be ridiculed by my friends if it didn't work. The one saving point was that the company guaranteed my money back if I wasn't happy at the end of 90 days. I'm a diver so I could take a look at the end of 90 days. I dove the boat at the end of the first month because I was curious. The bottom did have a slight film on it. When I went and brushed it by hand it came right off. So my guess is that it was dead algae. The unit cost me $1400 installed. So now that I'm at the end of my first year with no growth, I'm pretty close to covering all of my expenses. I used to have a diver clean the hull every month. Now that the hull and paint aren't being touched and scrubbed, I'm hoping the paint will last even longer. I'm pulling the boat to do my anodes and shaft seals in the next few months. I will post pictures of the bottom before it gets washed. I read dozens of posts before I jumped into buying one. Most of the postings were of the nature "If it's too good to be true..." I agreed with many of their views. I understand the technology behind it but I still had to see it for myself. I could justify the expense because there's nothing on my boat that doesn't cost me hundreds or thousands to maintain. So basically I'm satisfied with the first year.
 
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