Hi Steve
I don't know about passports but I did the 7 day Carnival out of Galveston in December 2021. I used my real id and my birth cert, no problems. We went to Cozumel, Roatan and Honduras. From what I have researched - if you're cruise is not staying overnight in the port, you do not need a passport. If course, always check with your cruise line.
Good luck and have fun!
Valerie K.