Here is a link to the NCL FAQ section about this matter
What if I need to stay in touch while away?
All of our ships have computer terminals you can rent by the hour at the Internet Café. You can also telephone, telex, radiogram or fax to anywhere in the world and be billed* at applicable ship-to-shore rates.
NCL guests can also be contacted on our ships by calling 1.888.NCSHIPS (1.888.627.4477) from the USA. For the rest of the world please dial 1.732.335.3280. When guests are contacted with the ship via satellite, they can be reached directly, if they are in their stateroom. If not, a message about the incoming call will be delivered to their stateroom and then they can call back* the shore via satellite.
NCL Ship Telephone & Fax Numbers
When calling from the United States:
Dial 1.888.NC SHIPS (627.4477), select the ship, and enter your credit card information.
When Calling from outside the United States:
Dial 1.732.335.3280, select the ship, and enter your credit card information.