坐船从悉尼去新西兰要签证吗？

http://www.immigration.govt.nz/opsmanual/42625.htm  
crew or passengers (including cruise ship passengers) on any ship carrying passengers or cargo or both (in the ordinary course of business of the ship) between any foreign port and New Zealand, will be deemed to hold a visitor (for passengers) or work (for crew) visa from the time the ship arrives at a port of entry in New Zealand until whichever of the following occurs first:the ship is given clearance to leave its last port of entry in New Zealand for that voyage, or28 days have expired, beginning with the day the ship arrived at its first port of entry in New Zealand on that voyage.
为什么官方的信息是说有课来自任何一个foreign port 要持有visitor visa才能进入新西兰呢？