Of course, the total cost of a cruise is airfare plus the cruise ship. The airfare varies depending on the location of the departure and arrival ports and what class you want to fly. If airfare is a significant part of the cost, you will get your best deals and most convenient times by booking far in advance if you are paying cash. There are special cruise fares that the cruise line or any travel agent can get for you once a cruise is verified, but, again, the cost will increase the closer you get to the cruise.

Conversely award travel miles required might go down as you get close to the cruise dates. For example, United may release more Saver awards close to travel time.