Assuming that going fishing isn’t just an excuse for you to go get drunk on a canoe, the Realsonar system pictured above might interest you. It’s an ultrasound device mounted on a buoy, which then communicates with your smartphone through Bluetooth. In this fashion, you get to see where the fish are up to a depth of 150ft. It works at about 4 frames per second, which should be plenty for you to cast your line in the direction and depth required.
But that’s not all the Realsonar does. There’s a Bite Alarm that lets you know when a fish is nearby, so you don’t even have to look at the screen (or even put your line in the water) while you wait. There’s also a mapping feature that lets you get an idea of the underwater topography, which is welcome to any boat owner that doesn’t want to run aground. Salinity and temperature sensors give you an idea of water conditions. And should you lose your buoy in the dark, you just press a button on the phone and it’ll light right up.
The Realsonar system is in the funding phase on IndieGogo. It’s $79 if you get in early, though there’s plenty of room right now.