I applied online, although most candidates are found through recruitment or cruise personnel agencies. Within a week or so I was contacted by the HR Hiring Manager in their Ft. Lauderdale Office. He was incredibly helpful and great at following up.
Once I passed a phone interview with him, I had a phone interview with managers and my future supervisors onboard the ship. It was a little intimidating as I was not warned ahead of time that I would be simultaneously interviewed by 9 managers. I was not offered the position but then a month later they contacted me again offering me the position but asking me to come into their office for an in-person interview, since I happened to live nearby. The interview was conducted by two high ranking individuals in corporate. It went well and they allowed me to ask a few questions of my own.
I heard back the following week and they gave me about a week to prepare and do all the paperwork before being sent to the ship's location.