Trips are always saved on this device first. Add a GitHub token to also keep them in a secret Gist, so your phone and laptop stay in step.
How close to the shore a track has to pass before that stretch counts as paddled.
A plain JSON file with every trip. Keep one somewhere safe.
180 km of Isle of Man coastline. Log each paddle, and watch the shoreline light up behind you until you have been all the way round.