There is no set-in-stone time, but it's usually between 11:30 a.m. and noon although it can be a little later. It all depends how quickly they can turn the ship around from the previous passengers.
11:45 in both February and March. We had group 7, and were on the ship before 12:05. DD didn't believe me when boarding started at 11:45 and I told her we'd be on in less than 20 minutes--she was whining about group 7.....it went very quickly.
I think my best time was 11.30am last year, we had boarding card '2' as a gift from a Disser, but we would have got '3' anyway, went on straight after Concierge then.
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