Other than relative acceptance of GPS in the former, one cannot compare sailing with flying.
This stating the obvious, but sailing is 2D, flying is 3D. If it wasn't for CAS, nobody would really care where people end up. And CAS can be infringed both laterally and vertically. It's got to be REALLY hard to make a nav error on a boat with a GPS showing the marine chart, yet one can still make a £5000 error in a plane with the best GPS available, because there is no vertical guidance.
In my FAA PPL checkride I was told very clearly that I had to know all the kit fitted. This included a GNS430 and a Stec 55X autopilot. The examiner got me to use it all, including using the AP to hold the plane in a 5 degree left bank orbit while I worked out a complicated diversion. This is exactly the correct procedure for any sort of emergency: autopilot comes on immediately and you sort out whatever needs sorting out. Airlines got thinking this way decades ago but in UK GA, you are supposed to grow an extra 0.5" of chest hair to demonstrate you are a real he-pilot. The old farts at the CAA must really love this stuff..........