Review on Portable Fish Finder for RICANK Water, Handheld Fish Detector Device for Ice Kayak and Shore Boat Fishing, Depth Finders with Sonar Sensor Transducer and LCD Display, Wired Gear Fish Depth Finder by Josh Garber

Pretty clear once you've finished the instructions you'll love the alarm feature, it makes it easy to use. Also suitable for mobile phone holder - see photo. Can't comment on portability - attaches to my fishing boat but I tried a float and it worked so I think it might be portable? Just like it can only be for below, managed to get two out of a lake I never got anything out of. I'm pretty excited to try more places where I haven't been bitten.