Royal Caribbean does have one of the best web sites for "jobs" information: like this:
http://www.royalcaribbean.com/ourCompany/career.do

You need to go to the cruise line web sites. There you will find a link to jobs, employment, human resources or some such link that will give you information about their positions. Use these web sites as a lead to who and where to write or call for information about positions. Some sites have actual vacancies listed and they also will list in general terms the basic requirements for working on a cruise ship. Many cruise lines use "hiring partners" who are agencies around the world who help them find and screen candidates.

DO NOT use any other web sites that require you to pay a fee to register or get job information or referrals. Carnival cruise line actually has a warning on its site about cruise jobs scams. Check this web link: http://www.carnival.com/cms/fun/fun_jobs/fun_jobs.aspx?icid=CC_Footer_104

Carnival is the parent company for several cruise lines including Carnival, Cunard, Princess, and Holland America. So contacting Carnival you can ask for leads to the other cruise lines also.

CARNIVAL:
http://www.carnivalcruiselines.com/

Then Royal Caribbean cruise line is a partner with Celebrity and Azamara. So you can ask for leads to these others.

CELEBRITY:
http://www.celebritycruises.com/home .

NORWEGIAN:
http://www.ncl.com/

DISNEY:
http://disneycruise.disney.go.com/dcl/..…

Another thing to do is to contact the concession that run the shops on the ships like the photo, souvenir, gift and clothing shops. These are also the companies that hire the beauty shop/spa employees for ships. Below are links for you.

http://www.steinerleisure.com/

and

http://www.hardingbros.co.uk/

The cruise lines also hire people to work on land at call in reservation and information centers around the country. Some are in Miami and others are in Seattle and other cities. In addition, they also hire part-time people to work at the port on the days when ships are departing. So when you contact the cruise lines you may want to ask about those type positions also. Keep all of your options for a job open and be prepared to wait a long time for the process to work.

Since you worked at Disney, you should for sure contact them about a job on a cruise ship. They may be your best best since you have prior experience with them
References :

http://allthingscruise.com/work-on-a-cruise-ship/

Good luck!
References :
allthingscruise.com

http://www.carnival.com/cms/fun/fun_jobs/fun_jobs.aspx?icid=CC_Footer_104
http://www.ncl.com/nclweb/cruiser/cmsPages.html?pageId=Careers
http://www.royalcaribbean.com/ourCompany/career.do

Hope I helped!
References :
frequent cruiser