It took us 15-20 min, but that was without any traffic to speak of. We got there about noon to board. The line wasn't long but we then had to wait in a big room for a couple of hours. The ship got in late and the passengers from the previous week were just getting off the ship at noon.
Celebrity Century 1/09
Carnival Destiny 10/07
Carnival Destiny 9/06
Monarch of the Seas 3/06
Carnival Inspiration 8/05
Carnival Miracle 4/05
Carnival Inspiration 4/04
Sovereign of the Seas 4/03
Under normal circumstances,if disembarkation went well and on
time that morning, checkin process can start as early as noon-ish....
Since lines at that time are never very long,it's a swift process and you
could be on board before 1.00-ish and have lunch on the Lido deck !!!