If, for whatever reason, you feel that the automated service charge should be increased or decreased, we’d recommend making this request at the end of your cruise. This allows you to evaluate how much would be a reasonable gratuity to give based on the service you’ve received during your time onboard. Any changes must be made before disembarking or the card you put on file with the cruise line will be automatically charged the sum total of your bill.
If you want to include any additional tipping, perhaps if you have received particularly outstanding service, generally speaking it’s wise to hand out cash tips on the last day of the cruise. Leaving it until the morning of disembarkation when everyone is extremely busy could make it difficult for you to locate the crew member you are seeking.
Certain exceptions to this rule include your room service steward, in-port baggage handlers and tour operators (the latter of which don’t work on the cruise) all of whom should ideally be tipped on the spot.