Cruise ships have had a rough few years.

From norovirus outbreaks to the occurrence of a ship slowly sinking off the coast of Italy, these floating resorts haven't made particularly good headlines. Of course, ships have always made people at least a little nervous. After all, Gilligan's three-hour tour resonated so well for a reason.

A ship at sea is a closed universe -- days from land, surrounded by salt water and the occasional shark -- so when something goes wrong, it's hard to get help and harder to get off. As such, it's important to keep accidents to a minimum, and the CDC conducts annual exams to make sure things stay that way.

Unfortunately not every ship scores all that well. On its 100 point scale, the CDC's Vessel Sanitation Program considers any score of 85 or below unsatisfactory. Here are the 14 ships at or near the bottom of the list.

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Editors' pick: Originally published June 27.