Presenting a negative PCR COVID-19 test at check-in, taken between 72 and 24 hours prior to the sailing date (for example, if the sailing is on Saturday, the test may be taken any time from Wednesday through Friday, but not on the morning of embarkation). Unvaccinated guests must take an additional antigen test at embarkation, and test again within 24 hours of debarkation on all cruises longer than 4 days. A US$150 per person charge will be assessed to the guest’s onboard Sail and Sign account to cover the cost of testing, reporting and health and safety screenings. Children under two are exempt from testing requirements
This was posted today. But I can't find it on carnivals website.