Ranger wrote on Jun 17^th, 2015 at 1:17pm:

3. If he wears it clipped to his PFD or clothes for quick access, it fell off somewhere along the way.

i've seen pics of magic with the spot clipped to his pfd. perhaps in a trip report. i lean toward number 3, and feel for mrs magic as mrs zski had a similar 'no contact' experience a couple years ago.
ST is right: "... despite the technology and the good intentions, the actual results can be worse worry wise as just going in the old school way."