Details from the investigation report of the February 5th grounding of the cruiser USS Port Royal, have gotten out. The report detailed the series of events that led to the ship running aground in clear weather. It all began when the ship left Pearl Harbor (at 8:45 AM) for sea trials (after $18 million worth of repairs and upgrades), its fathometer, which automatically determined the water depth, was broken. That should not be a problem, as long as you stick to areas that your charts show are deep enough. This was the plan. Then, about three hours after leaving port, someone switched the Voyage Management System (VMS, a computerized system that replaced paper charts) from GPS, to the less accurate backup (an inertial guidance system). There was a nearly three kilometer difference between the GPS and the inertial navigation system, and this was never noticed for the rest of the day, even though the VMS gave error warnings. Moreover, the VMS had not been calibrated the day before leaving port, but four days earlier. But the main problem was that, as the ship passed the airport, there were clear visual clues that they were too close to shore.
As a result of the grounding, the navy punished the former captain of the ship, along with three of his officers and an enlisted sailor, for "dereliction of duty." The cruiser ran aground on the first day of sea trials, after spending four months undergoing extensive maintenance. The ship slid into a coral reef in a channel close to Honolulu air port.
The 9,600 ton Port Royal has been in service for 15 years, and is the 27th, and last, Ticonderoga class cruiser to be built. It took four days to get the cruiser off the reef, which was done by removing about a thousand tons of weight from the ship. The ship hit the reef because key members of the crew screwed up. The shoal is marked on charts. The Port Royal draws 33 feet of water, and the shoal is 22 feet under water. The captain of the Port Royal was soon relieved, which is normal for a grounding such as this.
Initially, the only damage mentioned was to the propellers (the tips were torn off), and a leak in one of the sonar domes. There was no hull breach. But even then, it was believed that the propeller shaft and shaft bearings would have to be replaced as well.
The actual damage turned out to be far worse. The drive shafts and the steel supporting them were twisted out of alignment as the ship was rocked back and forth. It was feared that this damage could be so bad that the drive shafts, reduction gears and engines might have to be replaced.
The sonar dome had to be replaced, and the hatches for some of the missile cells (silos) were also twisted out of alignment and had to be replaced. Some of the sensors and antennae on the main mast were twisted out of alignment by the shock of hitting the reef, and had to be repaired or replaced. Instruments and sensors on the bottom of the ship were destroyed or damaged by the grounding. The water exhaust and intake ports in the hull were jammed with debris, and had to be repaired or replaced (otherwise the sanitation, air conditioning and ballast systems will not work)
So after one day of sea trials, the Port Royal was right back to the shipyard and dry dock. The ship is still there and won't be back in the water until next month. The total cost for repairs will be $50 million. There were no courts martial for those who screwed up the navigation that put the ship on a known shoal. Professional mariners don't do that sort of thing in clear weather and calm seas. But the careers of the four officers who received "non-judicial" (no courts martial) punishment are severely damaged, more so than the ship (which, unlike a naval officers career, can be repaired.)
It would have taken only one of the people on the bridge to notice that the VMS was out of calibration, or one sailor to note, as the ship approached the air port, that they were too close to shallow waters. No one did. So despite all the automation and navigation aids, and all the people on the bridge, the ship ran aground.