I'd like to have a GPS to relay coordinates in an emergency and also to locate where I am. Your view on the water is essentially two-dimensional. Without landmarks that you can identify, all you see is a green, grey or speckled line in the distance. I was paddling with a group on Squam Lake and one paddler was able to locate our position and save us several mile of paddling. His GPS showed our position on a mini marine chart with place and feature names, without forcing us to plot the GPS coordinates on a paper/plastic chart. Your going to spend between $300 and $600 for the GPS and also buy the marine charts on an SD chip. A device with a readable marine chart sounds like the gold standard.