Prefer something fairly cheap or inexpensive, that can detect water surface, with a range of mayby 10m.
Purpose: Detect the ground for precision landing, mayby mid-air barometer calibrations (altho doubt plane will be in air long enough for that)
So likely anything with a range of more than 5m (or exactly 5m) will be good enough, as long as water surface is detected - Want to do water landings too.
PS: Friends have two kayaks I plan to use anytime I do water landings
Do I even need one? Mayby I could get away with barometer only
Plane: Tundra V2