My family had a cabin at a high-elevation lake in NE Oregon. We fished it for years. Until I started using a depth finder, I never knew that parts of the lake were nearly 40 feet deep. There are other resources that provide depth charts for most lakes but I never looked to see if this was one of them. The depth finder, sinking lines, and fly patterns that I have learned from this website have enabled me to vastly increase my catch rate. The lighter battery that I posted earlier in this thread will allow me to use it more places. Sometimes I don’t use it, but like @Smalma said, it’s a tool for my lake fishing arsenal.