Sorry to hear about your situation.
IF you still have the broken tooth
that came off of the denture and you are able to approximate the 2 pieces together nicely, then there is a temporary fix for you. You have to be sure that the surface onto which the tooth broke off is also plastic. If the surface is metal, then this won't work.
What you'll need to do is try and clean the denture as best as you can. Then you'll want to let it dry for at least 30 minutes. Once you've allowed the denture to air dry, you can then carefully dab a VERY SMALL amount of superglue on the denture area and take the broken tooth and carefully piece them together. (You don't need to put additional glue on the tooth fragment.)
(Disclaimer: You have to be VERY CAREFUL here as you don't want to the superglue to get onto your fingertips. Superglue dries instantly when it comes in contact w/ skin.)
Once you have it pieced together, just let it sit for 5 minutes on a counter top (away from pets if you have any) and let it dry. Assuming all goes well, you have successfully, albeit temporarily, repaired your broken denture.
Keep in mind that this is a TEMPORARY fix, and the broken tooth is still very weak. It'll basically be good for smiling only so when you eat with the denture, you'll need to avoid the tooth as much as you can for fear of knocking it right out.
Hopefully the repair will last the entire cruise and go see your dentist ASAP once you're back from your vacation.
Good luck and remember to be careful when using the superglue. If you have a friend or family member with really good hand-eye coordination, it might be wise to ask for their assistance.
I hope I was able to provide you with the answer you were looking for.