"Edgar" wrote in message
...

"cavelamb" wrote in message
m...
Bruce In Bangkok wrote:
On Fri, 09 Jan 2009 18:58:49 +0000, Gordon wrote:

http://www.ultrasonic-antifouling.com/

Only needs 1 amp 24/7
Gordon

I had a look at the site referenced above and a couple of things come
to mind.

First of all the site seems to talk ONLY abut algae and never about
barnacles or other kinds of shell fish.

Secondly, I have an inside mounted depth sounder with the transponder
epoxied to the inside of the hull - very similar to the installation
of the system described in the reference URL. I have never noticed any
decrease in growth on the hull from using the depth sounder.

Finally, as the entire system consists of a transmitter and a power
supply generating ultra-sonic pulses the price of GBP 700+ seems
extremely high for the electronics involved.
Cheers,

Bruce
(bruceinbangkokatgmaildotcom)

There was a short review of this device in a magazine.
Not a lot of info - but a claim of "one amp - 24/7".

So what does that mean?

One amp hour - per hour?
That would be useful only tied to the pier!

It means one amp continuously flowing 24 hours/day so you would need large
deep cycle batteries which, according to Larry, you do not get unless you
go for the large golf cart batteries..
The earlier comment about the depth sounder is interesting because ISTR
that I read somewhere that a transducer working through the hull does
leave a clear spot.
But that is very different to keeping a whole boat clear.
As regards barnacles and other kinds of shellfish I doubt whether, alive
or dead, they are going to drop off once they become established so if
ultrasonic works at all it has to scare them off when they are small
organisms swimming around looking for a good place to latch onto.

Might work well on a material that transmits sound well like steel or
aluminum but 'glass?