Ultrasonic antifouling?? any good??

[bobatkins]

I purchased and installed the CleanaHull system with 2 emitters (one over the running gear in the stern and the other in the forward area near the speed and depth transducers) about 3 years ago on my Hunter 41 which is berthed in Marina del Rey, CA. While their equipment is very well designed and made the system didn't seen to do much (if anything) to reduce the growth of slime and algae on a boat with 2 year old bottom paint. The other issue is that their ultrasonic emitters are not sealed and corrosion resistant so the forward unit failed after about 8 months. It was located in the same hull area as the speed and depth transducers and would tend to get wet when the speed transducer had to be removed for cleaning.

In the 8 months that I used the system (without telling my diver), I extended my bottom cleaning to once every 2 months. My diver reported the bottom growth was essentially unchanged in that after 2 months it was noticeably worse as would be expected. I also noticed that my boat slowed down quite a bit requiring another 300-400rpm just to maintain 5 kts when compared to a freshly cleaned bottom. I asked him if he saw less growth around the hull area over the running gear or even the running gear itself and he reported nothing unusual in that the growth was even under the entire hull. I also noticed that growth on the speed and depth transducers and their thru hull openings was unchanged. This was disappointing because the forward emitter was within 16 inches of both devices and I would have expected maximum effectiveness in the general area of the emitter.

In the end I really wanted the system to work but it didn't for me and I wouldn't make the investment in another one.

---
Bob

[Sputnik]

Thanks Bob for a frank and well thought out critique.
Were you on shore power or independent power?
Neil

[fstbttms]

Originally Posted by bobatkins

...the system didn't seen to do much (if anything) to reduce the growth of slime and algae on a boat with 2 year old bottom paint.

Ultrasonic didn’t perform as advertised? That’s shocking, I tell you. Shocking!

[senormechanico]

2 transducers on a 41 foot boat?
The manual describes an effective radius per transducer of approx 7 1/2 feet.


I have 4 transducers on my 33' boat, and it works, running 24/7 on solar.


I do however, admit that my knotmeter which up til now has never gotten fouled, actually did foul the other day.

A quick brush with a sponge and it's back working.

[NakedCity]

Where is Practical Sailor when you need them ?

[Seman]

I have 4 transducers in each hull of my 48'cat. Ultrasonic antifoul does not work for me!

[Sputnik]

Originally Posted by senormechanico

2 transducers on a 41 foot boat?
The manual describes an effective radius per transducer of approx 7 1/2 feet.


I have 4 transducers on my 33' boat, and it works, running 24/7 on solar.


I do however, admit that my knotmeter which up til now has never gotten fouled, actually did foul the other day.

A quick brush with a sponge and it's back working.

Where are you based?
What antifouling paint do you have on the hull?
How long have you had the 'sonic system running?
Which one is it?
Do you lift/scrub each year?
Are you in the water year round?
How many Watts of solar do you have?

Me thinks that these forums could serve a better purpose......statistics speak......lies, damn lies and statistics......

Any one think of other Q's that could serve a better poll?

Neil

[Cadence]

I may have missed it? Has anyone given any thought to, if it works or not and how effectively, may be dependent on hull material and any other no. of variables.

[senormechanico]

Originally Posted by Sputnik

Where are you based?
What antifouling paint do you have on the hull?
How long have you had the 'sonic system running?
Which one is it?
Do you lift/scrub each year?
Are you in the water year round?
How many Watts of solar do you have?

Me thinks that these forums could serve a better purpose......statistics speak......lies, damn lies and statistics......

Any one think of other Q's that could serve a better poll?

Neil

Puget Sound in Washington State. Specifically, Whidbey Island.

Trinidad SR (April 2018), previously last 4 years Micron Extra.


UltraSoniTec 4 channel system since 2012 running 24/7.


Boat is in back yard at my salt water dock all year long, see photo.



No annual haulout, but if I feel like it and get in warm enough water (Desolation Sound) I might take a sponge over the side and slosh off the waterline.
That usually happens once a year.


Up until this year, 440 watts of solar with MPPT and single LiFePo4 200 aH bank.
This spring, I added another 120 watt panel as we added an electric flush head.

Boat is mostly used in the summer months.

[bobatkins]

Originally Posted by Sputnik

Thanks Bob for a frank and well thought out critique.
Were you on shore power or independent power?
Neil

I was on shore power in a slip the enture time that I used the system.

[senormechanico]

Originally Posted by bobatkins

I was on shore power in a slip the enture time that I used the system.

Bob,


Ultrasonic systems need a clean surface to start. If fouling is present beyond thickness, the existing layer will dampen the soundwaves and other fouling can adhere to that.

Think of the original stuff as earmuff protection for the new fouling.

[Sputnik]

Senormechanico, are there boats around you that suffer from fouling, or are you in a "clean" area?
Do boats around you with other types of antifouling suffer fouling?
As this "survey" progresses, it becomes clear just how difficult a meaningful survey is.
Neil

[senormechanico]

Grass in the summertime, barnacles and mussels year around.


I am digging around in my photo collection for some evidence BEFORE the ultrasonic, and will post photos.

[senormechanico]

Will this convince you?
This was after about seven months October to May of sitting at my dock.
Paint was 3 years old.
Ultrasonic had not yet been installed.
Last two photos taken just now.
Dock is new in April 2017.

[bobatkins]

Originally Posted by senormechanico

Bob,


Ultrasonic systems need a clean surface to start. If fouling is present beyond thickness, the existing layer will dampen the soundwaves and other fouling can adhere to that.

Think of the original stuff as earmuff protection for the new fouling.

Perhaps you didn't notice in my original posting but I had a diver cleaning my boat on a monthly basis as is the practice here in Marina del Rey, CA where in the summer months fouling growth is significant. Virtually everyone has a diver clean their bottom every month - and I was no exception. Also my 70% copper, Pettit Trinidad SR non-ablative bottom paint was about 2 years old at the time so it was still in acceptable condition. When I installed the ultrasonic system, the bottom of my boat had just been cleaned. I then rescheduled my diver to skip a month. I didn't tell him why and I kept him on an every other month basis for 8 months. I used an underwater camera to inspect the running gear and areas immediately around where the emitters were mounted. I could see no discernable difference in terms of slime buildup and algae growth with the camera. When I asked my diver what the condition was that found when he came every other month he said that the growth was heavier and what he would have expected for skipping a month. I asked if there were any areas of the bottom that were cleaner than others and he said it was all the same - quite even. Now he thought I was asking about the condition of my bottom paint - he had no idea that I was running an Ultrasonic system.

I could also see the decline in performance in between cleanings by my diver. I know that I can do 5 kts at 1400 rpm when the boat is clean. When I have to run 1800-1900 rpm to do 5 kts the bottom is quite fouled and that is what I experienced after 2 months in between diver cleanings.

Like I said in my original posting - I really wanted the system to work as I had made a $1500 investment in the system not to mention the time and effort to install it! I can confirm that it was installed and operating correctly for the entire 8 months until the forward emitter failed. Unfortunately, in my case it made no discernable difference in the growth of slime and algae - the two most fundamental types of growth that an ultrasonic system claims to be effective against.

Now after such a ringing endorsement, if anyone wants to buy the system from me - I would be more than happy to sell it. I even have a new replacement emitter that I never bothered to install.