John King talks about their Cessna 210 crash.

[Pace]

A handheld GPS, a handheld transreceiver (and maybe a mobile phone) can save you a lot of trouble...

As can airmanship and basic pilot skills /decision making both sadly lacking in this instance.
The GPS and handheld would have helped them but only they put themselves in that situation.
As in the other thread (Peter technology should add to basic airmanship and piloting skills and not be a substitute for those skills

pace