If your looking for a depth finder, Bottom Line has a model for you.
The Bottom Line Fishin' Buddy is the ultimate portable fish finder that has been helping fisherman find fish for over 10 years. This portable fish finder is so flexible that an angler can clamp it to a john boat, dingie, canoe, pontoons, rowboats, float tube or right to the dock.
Affordable electric downriggers like the Mini Mag and Magnum 10 (workhorse of the Great Lakes) make trolling with downriggers a pleasant experience.