Radio transmission using personal communication devices (including walkie-talkies, two-way pagers, or global positioning systems) is prohibited at all stages of flight
thems the rules brother either abide by them or expect the consequences
You cannot break that rule unless you create a radio transmission by using your portable GPS as a "personal communication device"!
I am still looking for that feature on my Garmin III Pilot and Garmin 496.
Dr 
PS: I wonder how many people turn off Bluetooth and Wifi when using a laptop on an aeroplane?
I suspect ................ NONE!