Before 1:25, HMS Devonshire's RN Commander (three rings of gold braid of equal length) asks
Are we absolutely sure of our position?
The Lt Cdr (two medium gold braid stripes with one thin gold stripe running in between) answers
Yes, Sir. An exact satellite fix.
After this screenshot, we see Carver's cyber-terrorist Henry Gupta meaconing the GPS signal using an encoder obtained at a terrorist arms bazaar, and Carver's company's satellite overtopping a US satellite. Gupta's undeniably hornswoggling the HMS Devonshire's satellite fix, but I don't know how.
Was Lewis Collins on YouTube correct? He proclaimed:
in reality they’d absolutely have a fix of their position without using GPS.... but that wouldn’t make for a very good film would it...