President Obama signed into law the Cruise Vessel Safety and Security Act. The act is basically regulations on how the lines will handle crime and prevention of it. Cruise Lines will now be required to report deaths and other such events immediately to U.S. authorities, as opposed to being very secretive as they were before.
Other elements of the law, on the prevention side, include elements such as mandatory peepholes and safety latches on cabin doors, most ships have them already. It also mandates that all ship railings be 42-in in height (3 1/2 feet). Originally, the law called for railings of something over 4 feet, which would have been ridiculous!
The law, which covers all passenger vessels of more than 250 pax (so the costal ships are not effected, although they are registered in the US, so they have stricter regulations anyways.) It will go into effect in about 18 months and it seems as though ships will have to meet the standard and won’t be able to be grandfathered in.