Port Royal had just completed $18 million in scheduled repairs at the Pearl Harbor shipyard and departed that morning for open-ocean sea trials. From the start, the ship was operating with known deficiencies: the fathometer, which measures water depth beneath the hull, was broken. At noon, someone shifted the automated navigation system's primary input from GPS to a Ring Laser Gyro -- an inertial navigator that estimates position based on the ship's own motion rather than satellite fixes. Three times, the Voyage Management System dead-reckoned the ship's location, each time placing it 1.5 miles from where she actually was. No one on the bridge noticed the discrepancy. The ship continued through her sea trial checks -- full power runs, steering tests, helicopter operations -- all while the navigation system quietly insisted she was somewhere she was not. Captain John Carroll, the commanding officer since October 2008, was sleep-deprived. At 8 p.m., the illusion ended when the cruiser's hull met a sand and rock ledge south of the airport's Reef Runway.

No one was injured and no fuel spilled in the initial grounding, but getting Port Royal off the reef proved far harder than running her onto it. Over three consecutive days, the salvage ship made unsuccessful attempts to pull the cruiser free, even as full-moon high tides offered the best possible water levels. The crew offloaded 200 short tons of fuel and water, 7,000 gallons of raw sewage, and 15 short tons of personal equipment to lighten the vessel. Nothing worked. It was not until February 9, at roughly 2 a.m., that a final effort succeeded. Crews removed an additional 500 tons of water and 100 tons of anchors and heavy equipment, and a salvage ship with seven tugboats pulled the cruiser free in about 40 minutes. Rear Admiral Dixon R. Smith immediately relieved Captain Carroll of his duties pending investigation.

The damage extended in two directions. For the ship, the bow sonar dome was destroyed, propellers and propeller shafts were wrecked, and the superstructure was cracked. Port Royal entered Dry Dock Number 4 at Pearl Harbor on February 18. The Navy estimated repairs at $25 to $40 million. Structural problems with the sonar dome rebuild and misaligned propulsion shaft struts extended the timeline -- the cruiser did not deploy again until June 2011, more than two years later. For the reef, the toll was equally severe. Laura Thielen, chairwoman of the Hawaii Board of Land and Natural Resources, reported the grounding had damaged between six and ten acres of coral and potentially harmed green turtle habitat. The main injury scar covered roughly 9,600 square feet. At a cost of $7 million, Navy-contracted divers collected 5,400 loose coral colonies and reattached them to the reef using cement and plaster of Paris, removing 250 cubic yards of rubble. Additional repair work planned for late 2009 was suspended when environmental experts concluded that reattaching more coral would do more harm than good.

In June 2009, Vice Admiral Samuel J. Locklear imposed non-judicial punishment on Captain Carroll for dereliction of duty and improper hazarding of a vessel. The executive officer and two additional officers received discipline, along with one enlisted sailor. The Navy declined to disclose specifics, citing threatened legal action by the state of Hawaii. The fallout extended beyond courtrooms. Navy command reportedly lost confidence that Port Royal had been fully restored to seaworthiness, and she appeared on a list of seven cruisers slated for early retirement, with decommissioning set for March 2013. A subsequent Naval Sea Systems Command assessment found the ship's condition comparable to others in her class, softening the verdict. But the grounding had already become a cautionary tale studied across the fleet -- a textbook reminder that a billion-dollar warship can be undone by a broken depth gauge, a misread display, and a bridge crew afraid to question what they were seeing.