Select guests on Seabourn Pursuit made maritime history with the discovery of a WWI wreck during a submarine expedition.

Carnival Cruise Line is one of the industry’s behemoths, operating more than two dozen ships that sail across the globe. But it also has a more dubious distinction of late, with three of its ships landing on the lowest end of the cleanliness spectrum, according to the Centers for Disease Control and Prevention.

Cruising is the only travel sector that routinely reports illnesses to the CDC and has scores posted in a central place, according to Cruise Lines International Association, which also notes that only 1% of ships have received failing scores since the voluntary program began in 1990 and and most ships score much higher.

Keeping up a 100-point ranking of cruise ship cleanliness that it updates for each ship every two years, the Centers for Diseases Control and Prevention (CDC) currently has 13 ships that fell below 90 points when it comes to cleanliness — of those,