As Bingley correctly points out, what they refer to as "navigational devices" seems to be power to the diesel-electric drive and steerage. That said, the Captain is always at fault for running aground. In this case whomever was in charge of navigation and keeping power to the screws is also at fault. It's fine to say let the investigation run its course, but the fact is a ship that was perfectly fine Friday morning is now lying on its side with casualties.

One article indicates they passed closely by shore to show off to the natives. Cute, until you lose power or sunspots or solar maxima screw up your GPS navigation. The point is that it doesn't matter why they hit a rock that wasn't supposed to be there, they hit it. Whether the rock grew bigger since their last cruise through that area or the tide was too low, or their navigation was off by 30/100/300 feet -- it just doesn't matter. The dog-ate-my-homework excuse just doesn't work here.

There's a reason I actively avoid cruise lines. YMMV