I am a Kuwaiti citizen holding a valid passport with a US tourist visa. I would like to go on a cruise around Alaska. The cruise stops at Vancouver, Canada for only six hours. Should I apply for a Canadian visa?
Yes, you need to apply for a Canadian visa. The length of the stay does not matter.
Do I need a Canadian visa if I have a United States visa?
Yes, you will still need a Canadian visa (temporary resident visa) to enter Canada. A visa from the United States does not permit entry to Canada.
If you are a permanent resident of the United States and have your Alien Registration Card (Green Card) or can provide other evidence of permanent residency, then you do not need a visa to enter Canada as a visitor.