A Ministry of Defence inquiry into the grounding of HMS Astute, the Royal Navy's most modern 'stealth' submarine, during sea trials in Scotland has issued damning criticisms of crewmen during the embarrassing spectacle.
"Then root causes of the grounding were non-adherence to correct procedures for the planning and execution of the navigation combined with a significant lack of appreciation by the Officer of the Watch (OOW) of the proximity of danger," the inquiry found.
In short, the OOW, who was in command on the bridge of the boat, got lost.
It also points to a number "of additional causal factors" which include equipment failures - among them of radar, and an audio board on the bridge.
The HMS Astute got stuck on rocks near the Isle of Skye during sea trials when it attempted to pull alongside another vessel to transfer men and equipment to the submarine, which is estimated to cost more than £1bn.
Officers on the bridge lost their bearings and inexplicably switched off the echo sounder which would have enabled the crew to get a real-time feed on the depth of the sea beneath the submarine.
There had been "no dedicated plan or specific briefing for the boat transfer..." The Navigation Officers workbook did not indicate any prior planning for the boat transfer.
"The chart lacked any clear position for the transfer and did not provide any instruction on when to slow down..." the inquiry found.
Astute is the first of three nuclear submarines in her class capable of spending unlimited periods at sea with a capacity to carry 109 crew.
It is equipped with Tomahawk Cruise Missiles and Spearfish torpedoes.
Its stealth technology has been developed to hide it from other similar under sea hunters, and to allow it to be used as a base for special forces insertions.
Its crews are considered among the most elite in the Royal Navy but on this occasion the skipper was criticized, and lost his command, for failing to properly brief his men.
On top of that the OOW did not have a chart on the bridge until it was "too late" so that he could not have "determined his position relative to danger" and had not set "trip wires", visual aides, "to mitigate against impending danger".
An internal communication system had broken down forcing the crew to use a conference call to speak to one another while a "voice pipe" proved totally inadequate.
The OOW also could have avoided running the boat aground if he had given the correct order to turn it, and it was difficult to understand him anyway because of the poor communications.
Head of the submarine service, Real Admiral Ian Corder, said that three crewmen had been either internally disciplined or suffered administrative action and that the 10 recommendations of the inquiry had been or would be fully implemented.