On Sun, 24 Jan 2010 14:41:09 +0100, "Edgar"
wrote:


"Bruce In Bangkok" wrote in message
.
snipped
.
Which does not mention the electronic method which makes one wonder
about the validity of the claims for the "sound system".

I seem to recall that this system was based on observations which showed
that the transponders of echo sounders remain free from fouling.

And it may well work, or work in certain instances.

However I think that my point is still valid, that I have never met
anyone who was using the system and if, in fact, the system is
something wonderful it would seem likely that it would be in use.

Cheers,

Bruce
(bruceinbangkokatgmaildotcom)