Many people are tempted to bring their own dryers, but most cruise lines don't allow it. I am not sure what Disney's policy is. The problem is that your big, powerful dryer draws a lot of current. While you might think that you little dryer is not going to hurt anyone, and that your hair is very important, you might want to remember that the biggest danger on a cruise ship is fire. Hair dryers, immersion heaters and other heavy current users pose a danger to you, and more importantly to others (including children) on the ship. Shipboard fires can be very serious. Generally, if the dryer in your room is not satisfactory, the line will give you a slightly more powerful one, but it will be one that they know is safe.