If the cruiseline has the recommendation of 1pm- that would be my suggestion too. International flights still have a 2 hour window recommended. If your airline is one of the ones that has the direct clearing from the ship, then without a ship delay- should be fine. Unfortunately- with unloading thousands of passengers now from the mega ships- being "first off" may not be the option it once was when the 40,000 gt ships sailed.
Be certain to take a cab and not wait for a bus transfer, if your airline is not participating in the expediated clearance.