We always leave our passports in the safe and use our driver's license as our photo id in ports.
There was one time when I was concerned about hubby and oldest son making it back to the ship from an independent excursion...but still did not want to take the chance of the passports getting wet (cave tubing)....
so I just made photocopies of the passports and put them in a ziplock bag and put that (with the money and Sail and Sign cards and a credit card) in one of those Carnival water resistant hard plastic wallet thingy that hangs around your neck.
Nothing got wet....and they made it back in plenty of time....
NOW we have the Passport cards that we do take onshore to use as ID....
COMPLETES THE FLEET
If it is Carnival and it floats....we have sailed it!
Hubby ... DIAMOND (every ship except the Carnivale)
Me ... DIAMOND (every ship starting with the Tropicale)
20 year old son ... DIAMOND (every ship starting with the Tropicale...he is the only DOUBLE Milestone under the age of 21)
24 year old son ... DIAMOND