I've never used one fishing but I'm thinking about getting a portable one to try and see how many fish are swimming in my ponds and the approximate depths. Kind of a relaxation and hobby thing. I see the prices vary widely and, as with most things, I'm sure the more expensive ones are better but does anyone have any experience with them? My deepest water is about 12 feet and just wondered how good of one would I need to pick up the blips of the fish pretty accurately. I have an Aquavue camera which would be nice in clearer water but I can't see much in my ponds unless a fish swims a foot or so away.

The inexpensive ones won't be of much use in a pond. They will tell approximate depth and not much else in my experience. In order to see much detail of fish and structure, you might be spending over $300.

I'm a fan of this one;

https://www.amazon.com/Deeper-Smart-Sonar-2-55-Black/dp/B01CQLVO5U/

The Deeper Smart Sonar PRO+ is small in size, easily portable, easy to cast or throw out (or drag behind), and using the WiFi mode the range is excellent. You can use GPS and maps to map your pond, snap a picture of something that you want to remember and add a note to that photo, it will give you surface temperature, the depth, the fish and what depth they are at, and the structure and bottom.

For $240 I don't think you can go wrong. My son and I take it to everywhere we fish and use it to map that new to us water and identify where the fish are and what depth.

I believe you can find some videos on YouTube showing how it is used.

Now that looks interesting. The people on the videos seen pretty impressed with it. Thanks.

Yes I say it is a contender for sure. I have the previous model Bluetooth only and this new model with WiFi. Both work as advertised. It is the best "poor man's viewfinder" I've found through research. It has helped me map our pond depth, structure, and where fish hang out. It also has helped us fish other bodies of water where we had no idea of depth, structure, or fish hangouts.