A Back to Back, also known as a B2B, is when you take multiple cruises in consecutive order on the same ship. This is a very common method of turning 2 one-week cruises into a 1 two-week cruise. It is used by many cruisers to save on travel expenses when you have to travel a long way to your cruise departure port.
The process cruise lines in the USA are standard between them as the US Customs dictates most of the procedure.
The cruise line will supply you with a note in your room after the first leg of the cruise telling you when and when to meet the following morning. It will usually be around the Atrium or in one of the lounges. This will depend on how many fellow cruisers are doing it along with you.
Once you meet there and all other guests have already debarked the ship. A crew member will escort you off the ship and down the gangway to a customs officer. You will then all proceed to clear customs, afterwards, they will then escort you back on board the ship. You will usually have an hour or so where you are the only guests on board. This takes place before general boarding for the next cruise begins.
As for how your luggage will be handled will depend on if you are changing rooms or not for the next leg. If you are staying in the same room you do not have to do anything. However, if you are changing rooms, you will usually place all your belongings on your bed and your cabin steward will see that it is all moved.
If your embarkation port is outside the USA. Most cruise lines don’t exit you off the ship as their local customs requirements are different. You will still meet in a lounge or other common place to receive your new ship cards, but then can go about enjoying the ship before the next guests come aboard.
Most cruises vary from 1 week to another thus allowing you to see different ports, however, be prepared as all entertainment will be the same on both legs. This allows you to pace yourself from leg to another and not to be rushed to see everything on the first leg.
Some guests will do a B2B2B which is just 3 cruises. One thing to make sure before you board the first leg of the cruise Is to call guest services and make sure that they have the two bookings linked together. This allows the ship and your steward to know that you are staying on board. If you don’t do this, you may need to exit the ship with all other guests and then go back through the check in process to get back on.