Sadly, there is much missing from that article stub. Such as where he was at the time of the incident, was there a pilot aboard, size/type of bouy, amount of damage, etc.
I highly doubt that an NJP Adimiral's Mast for loss of confidence was conducted based solely upon this incident. He must have done something seriously wrong, and for the sake of public face they are calling it loss of confidence and only letting out what they want to be seen.
I had a friend who drove a destroyer aground (on an officer's orders, because the officer didn't know his head from a hole in the ground), causing millions of dollars of damage and the ship needing a new bow. Pretty much the entire east coast fleet knew about what happened to the enlisted sailor, but what happened to the officer was brushed quickly into some need-to-know confidential file.
What's worse is the navy is going through a huge process of booting people out for the slightest thing anymore. Used to be the shipyards here really had to hunt for good trained workers. Now they have to turn people away because they are so overloaded with forced retirees, HYT personnel and those who were kicked out because of some stupid tiny technicality in the back of some unknown manual somewhere. I see it every day.