Running your ship aground. According to this story, the USS Port Royal went aground in "about 20 feet of water."
The Tico cruisers draw about 34 feet of water, so depending on the slope of the bottom, something seriously went wrong. I can't imagine that the charts around Pearl Harbor are inaccurate, so it seems that somebody lost the bubble on the navigation picture. Executive Officers were designated as the ship's navigator, so the XO's career is toast, as is the career of the OOD (probably the only one who doesn't have enough time in to gracefuly retire).
Running aground is almost always career suicide. There was a real up-and-coming officer in the late `70s and early `80s; he deep-selected for both lieutenant commander and commander. Less than two months into his command tour on a Spru-can, the ship ran aground while on an in-shore acoustics range somewhere off Florida. Rumor was that he said something along the lines of "XO, I think we're turning the wrong way" just before the ship grounded. That was the end of his career.
I worked on one grounding investigation of a smallish research craft commanded by a lieutenant and the result was the same, as it almost always is. Unlike rivers, much of the ocean bottom doesn't move that much and unless either the chart is wrong or there was an unavoidable event, touching bottom means the captain and a bunch of other folks get sent ashore for good.