Here is my contribution to my comedy community as far as performing on Carnival Cruise Lines.
Carnival has 24 ships. Most of these ships have their comics on board two at a time doing five thirty minutes sets each on the cruise. On most ships you don't work with the other comic on the same show, you do your own 30 minute set, there is a 20-30 minute break and the other comic does his or her own 30 minute show. On most ships there is no opening act, just a host who maybe tells an old joke, goes over the rules and schedule, and then introduces you. Most of your shows have pretty good sized crowds, between 200 and 600 people on average, but just like in clubs there are bad nights and bad showtimes where you might have to go up in front of twelve people.
The minimum requirement to work for Carnival is to have two completely different 30 minute sets, one of them tv clean and family friendly and the other completely uncensored. During your tv clean set there will be underage people in the audience. You are not supposed to repeat a single joke between these two sets. You don't do the same opening line, you don't do the same closer, you don't do the dirty version of your clean joke later. This isn't like doing an hour in a club, this is much more technical and complicated than that. This is writing all of your bits out on note cards and moving them around and pinning them to a cork board and crafting two different shows that have an opening, a middle, and an end and have flow. This is a huge challenge even for the most experienced club comic. Also, your uncensored show, depending on the ship, might just be censored. If someone who works for the ship tells you one of your jokes is inappropriate and you need to stop doing it, if you don't take it out, even if they are wrong and you are right, you won't get invited back. Most ship comics who are regulars have at least 3 different 30 minute sets, one clean and two dirty. Oh yeah, and on some ships you are expected to have another 5 minutes of tv clean, family friendly stuff for the welcome aboard show.
While 'boat acts' have a reputation for being hacks (and there are plenty out there, trust me) the most respected and most worked comics for Carnival, for the most part, are legitimate stand-ups with original material. If you can't do two completely different 30 minute sets and another 5 minute set without telling old jokes, repeating bits, or doing improv or crowd work, I wouldn't pursue this gig until you can. A good test, go with a friend to a one-nighter and open for them. Go up cold and do 30 squeeky clean. Then go up cold somewhere else and do a completely different 30 dirty. Do those sets on the same night in the same club if you can.
If you are really competetive and can't handle being the 'other comic' at the gig, I wouldn't recommend pursuing this gig. A comic who isn't as good as you on paper but has a lot more ship experience than you do is going to be a lot more popular with the crowd until you get comfortable on ships and with your broken up act. Many new comics come to Carnival and get competetive and try to do 5 different sets before they are ready and they don't make set lists or do the homework to make sure that those sets flow and go well. These comics end up getting burried out here and don't get much work. They would have done better, probably, if they just focused on the goal of putting together three different shows and repeating those sets more frequently to get comfortable with them.
If you have trouble doing your time, if you frequently go long or short, you need to get that worked out before coming to Carnival. If you can't get up at 3:00 a.m. to make a flight, travel all day, get no sleep, eat one pour meal and knock three shows out of the park that night, head to the gym, fix your diet and get that kind of endurance before pursuing this gig.
Also, most of the comics at the top of the request list for Carnival have written a new bit in the last year (not all, but most), if you aren't constantly working on new material, get back into that habit before pursuing this gig.
Okay, got all of that? Are you ready? Now, how to get booked on Carnival. Carnival is booked by David Carlow (this isn't a secret, it was in USA Today), if that name doesn't sound familiar to you, you probably haven't been doing comedy long enough to keep this gig if you got a shot at it. Every single major comedy festival has a representative from Carnival in attendence to scout for talent, every one. Also, Carnival frequently shows up at showcases in LA and New York (and other major markets) looking for talent. How do you get invited to a showcase or a festival? Step one is open mic, step two is getting booked to host at a club, as you get bumped up to feature and headline you should be able to get yourself invited to a showcase or festival through the clubs that you work. If you aren't working any clubs regularly, I would pursue that before trying to get booked on Carnival.
This is a great gig and it allowed me to do more than 400 shows last year for crowds that totalled more than 150,000 people, the work is steady and it pays well. I've gotten to work along side some of my comedy heros and being in Mexico and the Carribean doesn't suck either. I'm writing this because so many comics have contacted me privately to ask me these questions and I thought I would tell everybody at once. The most important reason why I'm writing this and putting it out there is to warn you, if you get this gig and you aren't ready, you aren't prepared and you don't have enough material, you can't fake or hack your way through it (in the old days you could have, but now it would be impossible) and you won't get invited back. If this gig gets offered to you and you aren't ready, it would pay off for you in the long run if you turned it down until you were ready. I'm rooting for all of you, I hope this helps.