Royal Caribbean has released the following statement:
Yesterday, as Adventure of the Seas was arriving to St. Kitts, the ship became aware of oil loss from the ship’s fixipod. Oil booms were immediately placed around the ship to contain the oil. Engineers required additional time in port in order to continue working on the issue
The fixapod is referring to the middle prop unit of the ship. The Voyager and Freedom class have two rotating azipods on port and starboard. In between the two, is a rear facing stationary pod.