Lota lota, oh boy, I've run out of hair for this week already, it might have been on this site about 2-3 years ago, or possibly Spoonpullers.com
Pigeontroller, I won't disagree depending on the body of water, however you don't get that kind of coverage shown on his F/F, similar to what I've seen on mine in deep water for extended distances.
Not sure, but I think the guy that wrote the article was Vanselena, he was into designing/building transducers. Haven't heard from him in quite a while.