^ This. For something as important as what documentation you need in order to be allowed to board the ship, don’t rely on a message board. Even if we (collectively) are right, we are not authoritative.
I mean, if there are some unique facts or special circumstances to your particular cruise that we are not privy to, whereby you actually do need a passport, what are you going to tell DCL at the port - “But, people on the DIS Boards told me I didn’t need a passport.....”?
Or you could just get passports.