I knew I was hooked on stillwater fishing when I bought a Fishin' Buddy fish/depth finder. As I alluded to in another thread, I had a chance to try the prototypes for a small finder that would work with personal floating craft... in those days, a donut style float tube. Bottomline sent two prototypes to Deke Meyer and he and I tested them in a bass lake. They were crude suckers. You had to attach a separate transducer under the float tube and the battery was separate from the screen so you ended up with wires running all over the place. They did work but were a hassle to install. Bottomline finally decided on a model that had everything self contained in a portable unit. No more wires running all over your float tube. They marketed the product as a portable fish/depth finder for small boats, float tubes and even for personal use from a dock. The personal use bit was nuts because you can't hold the thing steady enough for it to work unless it is firmly attached so using it by hand was silly. When Bottomline first sold the unit, it retailed for a 100 bucks. The model I bought included the side finder feature and that is desirable. Then Humminbird bought out Bottomline and changed the design. They changed the design for the better in some ways and not so much in other ways. The Bottomline held the batteries in the handle so they were easy to replace. Humminbird placed the batteries under the screen so you must remove the screen to replace the patterns. And the handle is easily broken off... which I did. But you really don't need the handle and can easily move the screen around without it. Eventually the first Humminbird I bought broke at the screen mount so I bought another one... this time I also bought the carrying case so it is protected from me breaking the dude when I'm not using it and it is rattling around in the back of my rig. The tool is very valuable when fishing a stillwater fishery for the first time. You can map the bottom for depth and structure and also determine at what depth the fish are holding... this helps you choose an appropriate fly line for presenting your patterns. Rivers are easy to read but a lake is not. The finder helps you read the lake bottom and increase your chances of catching fish. The downside is you may find the fish but it doesn't mean you can catch them. So frustration can become a problem. If you're a stillwater fly angler and don't own a fish/depth finder and someone is wondering what to get you for Christmas, the Humminbird 120 with the side finder would make a great gift. You can usually find them online for 150-170 bucks. Don't bother with the color model. It is much more expensive and the color feature eats batteries quicker than the black and white 120. Holders are available for the side of boats and pontoon boats or float tubes. Mine came with a boat holder so I had to buy one that works with pontoon boats. Just a suggestion you may want to pass on to Santa Claus.