Just back from a SOLD OUT cruise on the Celebrity Summit. Everyone was tested before embarking and it was a great success. No masks at all once you boarded. We did a back-to-back and we were tested onboard the day before we docked from first leg right on the ship. They have a complimentary Covid test team. If you're afraid, it's best not to cruise. For the rest of us, it's great to be back on the open seas!