Hey Troy, if you are primarily going to fish Erie i would not go with a DSI unit, a better choice for you would be the HDS 5 Lake Insight, Dsi is better for looking at structure, downed trees, stumps, brush, fish mark more like little specs or dots, compared to the normal hook shapes of a good broad band sonar, call me if you want i will be at Bass Pro Rossford tonight, we are # ! in sales for Lowrance in the country and have a great staff ....Ed 419-691-8470..Home # also have a couple used HDS 7s with only a few hours use...