Deeper's Pro Plus is a castable wireless sonar device that is easy to use and very portable.  It matches up to your smartphone, tablet or other smart device using an app called Deeper. The app comes with some handy features like a calendar, maps and even weather forecasts.

For kayak fishing, you get to connect the device with a flexible mount to the Kayak.  I managed to fix it to my Jackson Mayfly without any issues - see Part Two of the video review for how that is done.  The smart sonar ball comes with three holes: one for the flexible mount, one for casting from  the shore and one for casting from a bridge.  To ensure that you get it fully waterproof, it has two waterproof marks that need to be lined up correctly.

I compared the Deeper Smart Sonar Pro Plus with my regular fish finder, and the results were quite consistent.  The water temperature was similar within a few degrees, which could depend on the different locations of the fishfinder's transducer and the Deeper ball.  Water depths were also similar within half a foot, which could also be ascribed to location differences.  The app converts the dots to fish icons on the screen, which is quite a cool feature. I managed to locate fish with the Deeper Fish finder and got to catch a nice Lady Fish Eye and some other fish during my first test trip. 

Figuring out the app was a bit of a learning curve for me, but I ended up managing to create memos and store photos at certain locations.  The app recorded my fishing seconds and stored information such as the water depths, where the fish were located etc.  I was able to get home and just scroll through all of that and analyze the terrain and contours of the body of water I was fishing.

It was very easy to set Deeper up and to connect the phone to the fish finder.  The only drawback for me was my Samsung S7 Edge - it was hard to see the image well on my screen, especially when I had the sun over my shoulder.  I used it during a 4-5 hour fishing trip, and by the end of it my phone ran out of battery power.

I wanted to use the fish finder a couple of weeks later during a second, freshwater fishing trip, but unfortunately I had underestimated its battery time.  I was unable to connect to the Deeper Pro Plus until I had charged it again at home

All in all I think the Deeper Pro Plus is an affordable option well worth exploring.  It is very portable, easy to use and provides detailed information at a fraction of the price of what some other fish finders on the market go for.