I find GPS routes handy for someplace I'm going into or out of a lot, or a port I expect to arrive at in the dark or in the fog. I have a tricky channel to get to my mooring and it is handy to have all the waypoints lined up one after the other to get in or out in the fog. The other day I was going from Cuttyhunk into Narragansett Bay and we left in thick fog, it lifted for a bit, then descended like a blanket as we crossed the Buzzards Bay Channel, then lifted for Sakonnet Point, then chased us all the way up the river to Fogland Point, where it got thick just after we picked up a mooring. I had waypoints set for the entire route and I ran them not knowing when I would be able to see and not be able to see. However, I like to use a paper chart to get a big area view when coastal sailing especially, to get a general lay of the land. I will usually also input several key waypoints into the GPS that I anticipate I might use, but again sailing in New England a lot you have to always be prepared for fog. If visibility is good I pretty much sail by the seat of my pants if I can see anything, but I also have the paper charts out, the GPS on with waypoints loaded, a hand bearing compass handy, and chart plotters near the helm. I still take bearings once in awhile too.