uses standard GPX files. So, tracks from any gps
fine. Wherever people in the area you are in decide to share them, I have no idea. I don't think sharing tracks is very popular. Maybe if you share the areas you are interested in someone local to that area can chime in.
My suggestion for areas not charted well is to use SASplanet and make charts
imagery. I hit a reef following a track that was "guaranteed" to be safe. So, I would never trust a track from someone I have never met.