about 4-5 years ago, the baggage xray detected a 2-3" round diameter device in the bottom of my rollaboard with a couple arms on it. the TSA equivalent + help went searching for it. after an hour of searching, wife asked for what he was searching. he finally showed us the picture, and i dug out my very simple WW II wrist compass. i would not try a gps.

i had heard they took cameras upon exit. so on another trip, i registered it on the way in. that took more than an hour. i would not try a gps.