The NTSB report says that the captain's and staff captain's inappropriate inputs to the vessel's integrated navigation system while it was travelling at high speed in relatively shallow water, and the inadequate training of crew members in the use of integrated navigation systems, were major contributing causes to the incident.
The report adopted by the NTSB states that the Crown Princess was operating at nearly full speed when the second officer took the controls. Because of instabilities in the automatic steering system, the officer faced the problem of navigating a vessel that exhibited both increasing course deviations and high rates of turn.
The second officer took manual control of the steering and steered back and forth between port and starboard in increasingly wider turns. Rather than remedying the problem, the second officer's actions aggravated the situation, resulting in a very large angle of heel.
The captain quickly returned to the bridge and brought the vessel under control by centring the rudder and reducing speed. The NTSB concluded that the incident occurred because the second officer initially turned the wheel to port, when he should have turned it to starboard to counteract the turn.
With particular regard to use of the integrated navigation system on the vessel bridge, NTSB noted that both the captain and staff captain had made errors by failing to recognise that the integrated navigation system could be unpredictable at high speed in shallow water, and that the rudder economy and rudder limit settings on the integrated navigation system were inappropriate for the vessel's speed and operating conditions.
NTSB concluded that these errors stemmed from inadequate training and lack of familiarity with the integrated navigation system.
As a result of these findings, NTSB has issued a number of recommendations with respect to the training requirements for seafarers serving on vessels with integrated navigation systems.
Princess Cruises responded to the report with a statement of its own, and noted that many of the recommendations made by NTSB had already been adopted by the company following its own reviews of how such mistakes could be avoided in future.
"During the past year and a half since the incident, we have introduced many measures designed to keep a similar situation from occurring," the statement read.
?(This has included) enhanced training with an emphasis on integrated navigation systems, strengthened professional standards and oversight for our deck officers, improved bridge resource management and handover procedures, and increased bridge manning, including new professional advisors."