that the shipping company requires or you will not be allowed to travel.
different countries have different visa requirements for people visiting them. if you do plan on getting off the ship at every port to give your legs a stretch it is a good idea to make sure you check visa requirements before you go. booking through a travel agency you will not be allowed to board the ship unless you send certified copies of your visas, passport and medical certificate as well as any flight tickets home, well in advance of the trip.
would you travel the world by container ship?
this could be a life changing journey for someone fed 