Notice that the GPS receiver in the picture shows an altitude of 91 meters (~~ 300 feet).
That's important.
If Iran is spoofing GPS signals in order to lure us into a trap just across the real territorial line, then that vertical altitude reading would be in error proportionate to the desired horizontal Eastern error that they would need.
Or put another way: if that altitude can be confirmed at the time of the picture, then Iran is truly in error and there is no trap (i.e. our guys were where they were supposed to be, not across the line on the Iranian side).
On the other hand, if that altitude on the GPS display is incorrect, then we have proof of Iran's GPS signal jamming/spoofing.
Look, its all just noise.
Iran wants war, and we are going to have to give it too them. Bush and Blair need to resign themselves to the obvious.
Ministry of Defence "On Sunday morning, 25 March, HMS CORNWALL's Lynx conducted an overflight of the merchant vessel, which was still at anchor, and once again confirmed her location on Global Positioning System equipment. Her Master confirmed that his vessel had remained at anchor since Friday, and was in Iraqi territorial waters."
In order to jam or "spoof" GPS signals, you need to be between the satellites and the receiver. Because receivers rely on signals from several different satellites to compute a solution, you need a jammer very close (and above) the receiver being jammed. In short, Iran is not having any influence on our GPS systems.