When you book and pay your fare you are agreeing to the terms of the cruise line contract. You are unlikely to be given a copy of it but can access it online, in the brochure or requesting a copy from your cruise agent.
Here are a few things to be aware of:
Refuse to let you cruise: You are likely to have agreed that the line can refuse to take a booking or carry you for any reason. They will only refund the cost of the cruise if they do.
Search rights: You are likely to be consenting to searches being made of your person, baggage or other property, and to the removal and confiscation or destruction of anything the line feels is a safety issue, illegal or will adversely affect other passengers and crew.
Independent contractors: Many of the facilities on ships are contracted out to third party providers like hairdressers, manicurists, masseurs, spa operators, photographers, entertainers, instructors, lecturers and excursions. The cruise line may offer no guarantees, warranties or recourse with them for any issues you have with these.
Photographic and video images: The line usually require you to give them the copyright to any photographic or video content they take of you, including allowing them to use them in advertising and publicity material without any payment.
Some contracts will give them the right to restrict how you use images and videos you take on board, including asking you to remove it from online sites.
Legal disputes: Most contracts will specify which court of law has to be used in the case of any legal dispute. These are chosen in areas that are usually more favourable to the cruising industry and may not be where the line is headquartered.
So make sure you are checking what you are agreeing to when you book and pay your final balance to avoid any surprises.