can spot mines, not reefs
 

http://photoblog.nbcnews.com/_news/2...ines-reef?lite

when i first saw the story yesterday, she'd already been stuck 22 hours. i said, wow, they can find small mines in a big ocean, but can't spot dangerous obstructions?? they tried to float her off at high tide, as you can see that was a failure.
the second picture also illustrates that captains future in the navy.