I think you should consider more than your EDC. Situation specific challenges that might arise could include failure of the cruise ship to provide adequately in any of the survival categories, plus the basic failure to keep you afloat. No EDC is going to be able to address all these challenges, so perhaps your luggage might include something in the nature of a maritime-adapted BOB

You are placing your life in the hands of the cruise line in many ways. Bug out is probably not a realistic option for most of the cruise, for example. But with well thought out EDC and BOB-type luggage you could be prepared to “bug in,” on the ship, or onshore

A cruise would seem to offer just another environment for the same old survival preparedness challenges. If you are serious, then examine your kit against the Rule of Threes (you may die if you go: 3 minutes without air, 3 hours without shelter, 3 days without water, 3 weeks without food). And then I suggest checking to see if you have gear in each of whatever survival categories you salute; at this time mine include First Aid, Shelter, Fire, Water, Food, Navigation, Light, Signaling, Self-protection, Hygiene, and Morale.

Manmade restrictions on gear in an EDC or BOB would include at least the cruise line gear prohibitions, TSA gear restrictions if air flight is involved, and as Bill Liptak pointed out, the restrictions of various countries you will be visiting. Lots of homework is in order; hopefully the cruise line provides adequate guidelines. You might also check online for the State Department guidelines and travel advisories, and by phone or online with the relevant U.S. embassy, consulate, or whatever couldn’t hurt.

Also, you will be in close quarters with a lot of unprepared people who could be pretty desperate in a survival situation. You probably want to keep your preparations secret, perhaps even from your traveling companions.