Re: 6 Americans, 1 Brit vanish at sea
"Two GPS positions from Niña's Iridium phone were 700 miles apart, even though the reports were sent within just seven minutes of each other. "
Not necessarily a mystery. if the phone was taken out of a box after extended non-use and travel, the last sky sight position would still be in memory, and presumably transmitted with the first call. One or more minutes later, the GPS would have refreshed and updated the position, so presumably the second position would be more likely to be the real one.
But NGA considers themselves to be part of the intelligence community and deals with civilians only to the extent that they are forced to. There's also a big difference between monitoring satellite calls in real time, versus what may or may not have been logged two months ago. As to their competency and whether they put a ship on a reef...remember, this IS the military intelligence community. If someone says "oops, we make lousy maps" you need to remember that the Russian cartographers were the finest in the world under the Czars. Then the Soviets literally misdrew entire villages and rivers on their maps, to ensure invaders (Hi, JFK!) wouldn't be able to use those maps against them. Sure, our maps are no good. Or is that a convenient disinformation?
Either way, putting one's hopes in the NGA is probably worth less than consulting the Oracle of Delphi. Or asking the NSA to task satellite coverage in the area where a liferaft might be now.