When our now 3-yr old son was 14 months old, we took him on a cruise to Alaska. We really enjoyed the fact that we only had to unpack and pack all that "baby stuff" once, but saw several ports. Also, the staff was great about entertaining him - especially at dinner. Probably the only downside was that we tried to get him to bed somewhere close to his regular bedtime and get his nap in the afternoon, so we had to arrange our schedule around that. We're taking him on a 12-day cruise to Hawaii in a couple of months! I wouldn't hesitate to take an 11-month old.