If you were planning on buying maps for the lakes you can look at Fugawi's list of compatible devices Here and see if any are there that you were going to get. They make a lot of maps and are partnered with Navionics which has over 17,000 US lakes and over 1000 HD maps with 1' contours. You can probably also download other maps just so the device won't freak out when you are off the road depending on the model and the people that make it.