Do I need a visa for a cruise ship stop in Sanya(Hainan)? Canadian ciitizen

No, the visa on arrival is available for you if you are traveling on international cruise ship who disembark in Haikou or Sanya.

The Ship is only in Sanya for 9 hours - I am NOT getting off (maybe only take a Tour.... do I need a Visa - or not?

If the ship will sail to a third country or region instead of the last one you come from after staying for 9 hours in Sanya, you may be able to enjoy the 24 hour direct transit in Sanya, and then no visa will be needed, but you’d better confirm that with the cruise ship company.