http://www.cabelas.com/cabelas/en/te..._A&_DAV=search
I' ve got one of these for my kayak and can' t complain. Its perfect for what you need as the transducer can be attached to a line and floats on to of your hole or can also be used in the summer. Just attach to a spare rod and cast out. or tie and drag from your boat. A bargain at only 170$ they do sell a smaller version (less pixcels ) for 80$ good luck.