this is my first post i think this forum is great. i'm looking for a fish finder for less than $200.00. i was looking at this garmin one from walmrt.https://www.walmart.com/catalog/product.do?product_id=4660395 I will be using it mostly for trout and cokanee. i fish a shallow lake quite a bit, it is less then 15' deep. any input anyone has would be great.