These are the 10 dirtiest cruise ships, according to the CDC — including an ultra-luxury vessel

• The CDC randomly inspects and scores cruise ships to prevent the spread of stomach viruses.
• Vessels inspected so far in 2024 have scored an average of 95.7 out of 100. A score of 85 or less is considered unacceptable.
• The dirtiest ships this year so far scored 89 or less, including one that received 62 points.

On most exams, a "B" is considered a passing grade.

For cruise ships, scoring an 85 out of 100 on the Centers for Disease Control and Prevention's Vessel Sanitation Program review is considered a failure.

The CDC has reported 10 bacterial and viral outbreaks on cruise ships since the start of 2024. Most cases have been norovirus, as these often-packed floating hotels can quickly propagate the highly contagious bug through contaminated water, food, surfaces, and people.

If you're one of its unlucky victims, it could quickly ruin your vacation — the four predominant symptoms of norovirus, also known as the stomach flu, are vomiting, diarrhea, nausea, and stomach pain.

To mitigate these outbreaks, the CDC randomly conducts sanitary inspections on cruises without prior notice to the vessel. The public health agency then scores the ship from zero to 100, with outcomes of 85 or lower considered inadequate.

The review includes checking common spaces such as kitchens, hot tubs, and children's activity centers.

Obvious issues, such as vermin and improperly stored foods, will dock points. So will less-apparent issues, such as buffet handwashing stations with light sources less than 110 lux and the swimming pool's hair and lint strainer not being disinfected frequently enough.

The CDC has performed 119 inspections so far in 2024, including repeat inspections on five ships. The average score is about 95.7 — 20 vessels achieved perfect marks.
But 10 vessels didn't break into the 90s range, including one that failed to pass, and Ritz-Carlton Yacht Collection's ultra-luxury Evrima:

1. Crystal Serenity — Crystal Cruises, scored 89 (inspected February 3)
2. Carnival Elation — Carnival Cruise Line, scored 89 (inspected March 14)
3. Adventure of the Seas — Royal Caribbean International, scored 89 (inspected January 23)
4. National Geographic Sea Bird — Lindblad Expeditions, scored 88 (inspected July 25)
5. Carnival Miracle — Carnival Cruise Line, scored 88 (inspected April 21)
6. MSC Magnifica — MSC Cruises, scored 86 (inspected May 17)
7. Evrima — Ritz-Carlton Yacht Collection, scored 86 (inspected February 9)
8. Carnival Breeze — Carnival Cruise Line, scored 86 (inspected March 21)
9. Caribbean Princess — Princess Cruises, scored 86 (inspected March 20)
10. Hanseatic Inspiration — Hapag-Lloyd Cruises, scored 62 (inspected September 29)

An 11th vessel, Margaritaville at Sea Paradise, received a failing score of 83 on May 1 but passed a subsequent inspection with a 92 on July 2.

The CDC performed 181 cruise inspections in 2023. Only one, MSC Seaside, hit below 85, scoring 67 when it was inspected in April 2023. However, it was reinspected three months later and received a 92.

According to the public health agency's cruise review database, since 1991, 50 ships have received scores below 85, with 75 total failed inspections. Hanseatic Inspiration is tied with Rederij Clipper Stad Amsterdam's Stad Amsterdam for the sixth-lowest score ever, though the latter most recently received 91 in 2019.

The CDC's review of Hapag-Lloyd's vessel noted violations such as a maggot-infested decomposing bird under the outdoor grill and dead insects in areas with food.

What the cruise lines have said

A spokesperson for Hapag-Lloyd told Business Insider the score didn't reflect the company's standards. Following the inspection, the cruise line conducted an internal investigation and "intensive training sessions with external and internal trainers," it said.

It plans to submit its corrective report to the CDC on time (the Vessel Sanitation Program manual states companies must submit their "corrective-action statements" within two weeks of receiving the CDC's final report).

A Crystal Cruises spokesperson told BI most of Crystal Serenity's violations were "operational items" that had since been addressed and corrected "through harmonization of procedures and additional training with our crew."

Similarly, a spokesperson for MSC Cruises told BI it had implemented an "improvement plan" on MSC Magnifica according to the CDC inspector's suggestions. Many of the changes were immediate and only needed "minor" efforts, it said. The cruise line said that it believes Magnifica's score "is not a true reflection of the ship as it is today" and that it would "welcome any future inspection."

MSC noted that many of its ships frequently achieve above 90, including the MSC Meraviglia and MSC Seashore, which both received perfect marks in 2024.

Carnival, Royal Caribbean, Lindblad Expeditions, the Ritz-Carlton Yacht Collection, and Princess Cruises didn't respond to a request for comment.

Correction: October 17, 2024 — An earlier version of this story misstated how many cruise ships had failed CDC inspections so far in 2024. Two ships failed, though one later received a passing score. The story was updated to clarify that the ship's second score was not low enough to be included on the list of lowest scores.

The story also misrepresented some CDC figures. The numbers 119 in 2024 and 181 in 2023 referred to the number of CDC inspections, not the number of individual ships inspected. Similarly, 50 different ships, not 75, have received failing scores since 1991, with some doing so more than once.

The story also misstated how many ships have achieved perfect scores in 2024. Twenty have done so, not 19. The story was updated to clarify that most ships in 2024 have scored at least 95, not 95 exactly.