Attract fish by sound, light or anything else

[i3layli]

My project right now is the depth finder. I've been looking at fishfinders and how they work and I think that's probably the best way to go - run an electronic input into a transducer and send out a fairly low-frequency sound wave since the lake will probably be deep. (Erie/Ontario).
However, I've been looking for such an ambitious soul who has posted such a schematic but no such luck. I'm a little sketchy on how to make a reciever that will take it the returning sound waves. Can anyone lend me their Genius?

[grifftech]

green fish light, like these https://www.amazon.com/s?k=green+fishing+light&crid=3B24G0V264T7A&sprefix=green+fish%2Caps%2C177&ref=nb_sb_ss_i_1_10

[ebastler]

My project right now is the depth finder. I've been looking at fishfinders and how they work and I think that's probably the best way to go - run an electronic input into a transducer and send out a fairly low-frequency sound wave since the lake will probably be deep. (Erie/Ontario).

One of us is a bit confused -- either you or me. 

Do you want to attract fish, as per the post title, or measure how far the fish (or the lake bottom) is away?
Why do you think that a deep lake (long distance) requires or favors low-frequency sound waves?

[windsmurf]

Some good info here:
https://www.eevblog.com/forum/projects/fish-finder-sonar-circuits-protocols-and-transducers/

You can start off with a cheap one to study here:
https://www.ebay.com/itm/LUCKY-FFW1108-1-100M-Fishing-Sonar-Wireless-Fish-Finder-Alarm-Sensor-Transducer/312624224834