Most Cruise ships adhere to the European electrical standard for wall outlets. Generally, these are the 2-prong outlets that are circular. American plugs have two small vertical slots and a round lower one for ground. European alternating current is 240 volts; in the USA, we use 110 volts. Most modern electronics can be used on 110 or 240 systems as they have internal transformers to step the voltage down. Your Laptop can run on either. Check the instructions manuals for your phone, tablet and device chargers.
When you get to your room you will notice that in the bathroom there is one American outlet- but that is for electric shavers only. Hair dryers or anything that heats up draws large amounts of current and should not be used in this outlet.
Most cabins have several European outlets and usually only one American outlet on the desk. If you plan to leave your room and work in a conference room or in the observation room, etc., your computer is probably designed for America use, so you will need to get an adaptor. On stage during your talk, you will have the American adaptorsupplied by the technician.