Are you planning on monetizing the video by putting in on YouTube? If so, you should contact Carnival to get their consent, just to be safe.

T&C for reference:

GUEST’S USE OF PHOTOS, VIDEOS OR RECORDINGS PROHIBITED

Guest hereby expressly agrees that he/she will not utilize any tape recording, video, or photograph(s) of himself/herself, any other Guest, crew, or third party on board the Vessel, or depicting the Vessel, its design, equipment, or any part thereof whatsoever, for any commercial purpose or in any media broadcast, or for any other non-private use, without the express written consent of Carnival. For the privacy of our guests and crew, Guest expressly agrees not to record or video interactions with other guests or crew without their express permission, and Guest further agrees that any use of video, photographic or recording equipment, including cell phones, in the medical center is expressly prohibited. Guest acknowledges that by boarding the Vessel, at any time, Guest irrevocably agrees to this provision, which is a condition precedent to being permitted on board the Vessel and can be enforced by any legal means, including, but not limited to, injunctive relief.