Humminbird 120 Fishin' Buddy 4-Inch Waterproof Fishfinder
Use it on your boat, your buddy's boat, a dock, or even a float tube .  Fishin' Buddy Fish finders give everyone the ultimate in portability, with an ergonomic clamp mount design you can use nearly anywhere, with absolutely no rigging or wiring, or even a transducer to mount.  You'll love the high resolution monochrome display and powerful SideFinding sonar that you can point in any direction to find more fish.   The 24" transducer tube housing reaches the water from most small or mid-size fishing boats.