To help you plan your packing, I've developed a packing checklist that may be helpful. Also, as you plan for your trip to Greece you need to consider the electrical service which is quite different than that used in the United States.
Unlike North America, most of the world's electrical service is 220-240 volts at 50Hz. In the US, electricity is usually delivered at 120 volts and 60Hz. You'll also find that the outlets look quite different from what you see in your own home.
Before we continue, you have to consider what you are bringing. Any device that uses electricity are divided into two groups.
Electrical Devices: These are devises that have heating elements or mechanical motors, the most common being;
- Hair Dryer
- Electric shaver or toothbrush
- Coffee Maker or water heater
Electronic Devises: These items use circuit boards and chips, the most common being;
- Laptop computer, tablet, e-reader etc.
- Smartphone or MP3 player
- Battery chargers
My recommendation is to leave any electrical devises at home. You'll find a hairdryer in every cabin on the ship and in the hotel. If you really want to bring an electrical device, you'll need to figure out the voltage requirements. If it is a dual voltage device, then all you need is a plug adapter. If not - like most hair dryers, curling irons etc. - then you would need a voltage converter or transformer in addition to the adapter plug.
Just know, I've seen hair dryers that were plugged into pretty decent voltage converters and still burned up.
For all your electronic devices you'll find that most of them will work at any voltage and all you need is an adapter plug. Adapters are inexpensive and are often sold in kits. You don't need a kit with a transformer and every adapter for international travel. These tend to be an expensive waste of money.
For Greece, you'll use a Euro style adapter that is simply two round prongs. If you're going to spend any time in the UK, you'll want to have a Great Britain style three-prong adapter.
You can buy these adapters online - REI has a nice selection at www.REI.com - or in your local Home Depot. Home depot has a nifty all-in-one Travel Smart adapter and even one with a USB charing outlet.