As the topic describes, I'm working on my robotics project again after a 8 year hiatus. I remember reading in a book somewhere--not sure if it was gordon's or david cook's--about coming up with some sensor ideas for sensing the edge of, say, a table. Seeing as my testing grounds include a large pool, I think it would be a good idea to mount a ground facing sensor to detect edges/cliffs/etc. Any suggestions on a suitable sensor for this application? IR? Sonar? Would those be able to detect water? Any input is appreciated, thanks!
-Chris Alas