The chances of you getting the ship you 'request' are slim to none on your first contract unless they just happen to need people on that ship and you get lucky. Seniority is how many of the assignments are made. There really is not one 'best' time to apply, you just do and wait for them to call you. Some folks wit a very long time and some never get called and I have known others that were signed into a contract in a week! Luck of the draw and who and what5 they are looking for. My advice is to talk to some employees and let them know you are looking for a job and what you are wanting to do and have them tell you what it is really like without the hype. Working on a cruiseship can be very rewarding and a fantastic experiance but it is lots of very hard work and lonely.