So . . . let me give you a "second opinion" ;-)
I worked for RCI for a dozen years. On the 'mid sized' ships, we had 3 people. the larger (Freedom and Oasis class) there might be 4? I'd say 1 out of every 5 or 6 IT people were from the US. UK, India and eastern Europe are the norm. Tattoos on that line are OK (non-offensive, saw a lot of arms, legs and a bit of hands, back of neck).
The IT peeps do work some LONG hours - be prepared NEVER to get off on a turnaround day (keeping guest check in at the terminal going smoothly). Sea days are busy due to shops/bars POS machine issues. As far as shore leave - there is always a 'duty guy' left on the ship, not an issue when you have a bigger team. RCI IT people who are not the manager will be sharing. BUT - they are going to be nicer, outside cabins.
Here are some links for you - as far as breaking in, google every cruise line and look for their 'careers' site - also look at sites like monster or indeed.com.
Royal Caribbean job site
Royal Caribbean Shipboard Careers
In addition to the online headhunters, they use outside agencies or 'hiring partners' to screen - so here's the US one
Seven Seas Group : Home : Recruitment for jobs on cruise ships.
And I dug thru my old posts as I KNEW this topic has been covered but the search on this site wasn't bringing it up - a job description
IT Positions onboard
more RCI related sites
RCI/Azamara/Celebrity hiring websites
Good luck and post back here what happens - many people find this forum when looking for jobs on ships.