What I suspected. So you are just looking for a way of displaying the signal from the transducer.
This might come from a variety of displays.
https://www.ebay.com/bhp/depth-sounder
Here are a few examples.
Granted it’s ebay. You can also look at WM.
You might find the display at a boat consignment shop.
I wanted to get the depth to my Raymarine SeatalkNG backbone. I used the existing transducer that was in my hull. I connected it to an iTC-5 unit that takes the signal and translates it into a numerical depth number. This number is available to several displays. My iPad, my laptop, my iPhone and my AP display.
There are many options. What path interest you?