Holiday visa for South African Citizen

Dear Sir or Madam,
My wife is a South African citizen, by birth and at the moment is employed as Nursing Officer with the, Fred Olsen Cruise Lines on the Cruise ship SS Balmoral. The ship will be visiting China and Hong Kong, Japan and South Korea in March, 2015, as part of the World Cruise. As from 1st March 2015 until 16th March 2015 and on the cruise ship she will be classified as a passenger and not as an employee. She has a "Seaman's book" which allows her to enter different countries while employed to take part in organised excursions. Will this be good enough for my wife to take part in organised excursions ashore or will she require a separate permit?
We have only been authorized to take part in the cruise about one week ago and my wife has already left South Africa five weeks ago to work her present four month contract.
Thank you for your help in this matter.
Thomas WL Condie