The Centers for Disease Control and Prevention (CDC), the mastermind of the Vessel Sanitation Program, regularly and without warning inspects cruise ships carrying more than 13 passengers and with itineraries including the USA.
The latest of these results, often updated, can be found at www.prowsedge.com/cruise-lines-vessel-sanitation-program.html
Generally results of 96% and more are very much acceptable, those below 90% begin to ensure that you look out for the next inspection and hope for an improvement. Anything at 85% or less is not considered to be acceptable.
Some cruise lines often feature a number of their cruise ships coming up with 100% scores.
Of the cruise lines with a huge number of large vessels each, five of the Royal Caribbean Cruise ships, four of the Carnival Cruises ships, four of the Princess Cruises ships, four of the Norwegian Cruise Line vessels, and two of the Holland America Line ships, have each earned the 100% score.
Of the smaller cruise lines, with smaller ships, top scorers include vessels of P&O Cruises, Oceania Cruises, Silverseas, and Cunard Line.
For full details take a look at the latest scores updated on 6th March 2012 at www.prowsedge.com/cruise-lines-vessel-sanitation-program.html