And your dead-line for checking in is even earlier if you have not completed all your check-in information on-line, at least four days prior to embarkation. Homeland Security requires the cruise line to provide the final passenger list, (with all the required info) 60 minutes prior to sailaway, so if you don't do the on-line registration, you must arrive 90 minutes before the scheduled sailaway time.
And Michael is right about that 11 am boarding. Your documents will likely say boarding begins at something like 1:00 pm, but most cruisers will be at the pier much earlier. And they usually do start to board much earlier than the time stated in the cruise documents.
This is always a point of contention between me and hubby. I'm the kind of cruiser who would arrive at 10:00 am if I could talk hubby into it. I don't mind the wait in line at all. In fact, I find it kind of exciting.
But Hubby's the kind who would really rather wait until the almost everyone is onboard, and the line is gone. We've done both ways at different times. Either way we always arrive in the embarkation city the day before, so our arrival time at the ship is just a matter of what time we catch a taxi from the hotel to the pier. Never, never plan your arrival into your city embarkation any later than five hours before sailaway. (And even that would make me a nervous wreck.)