It is very confusing. We board the Royal in Whittier on Sept 10th. Take a look at the Canadian Government Travel website: https://travel.gc.ca/travel-covid/travel-restrictions/cruise.
COVID-19: Cruise ship travel requirements
Pre-embarkation COVID-19 testing
Pre-embarkation COVID-19 testing All travellers 5 years of age or older must have a COVID-19 test to board a cruise ship in Canada or to board a cruise ship that will dock in Canada at any point on the cruise. You must provide proof of one of the following accepted types of test results:
Proof of a professionally administered or observed negative antigen test taken no more than 2 days before you’re scheduled to board your ship
the 2-day window does not depend on the time of day the test was taken or the time that you board
for example, if your ship is scheduled to leave on Friday, you could provide proof of a negative result from an antigen test taken any time on Wednesday, Thursday, or on Friday
it must be administered or observed by a pharmacy, laboratory, healthcare entity or telehealth online service
the test must be authorized for sale or distribution in Canada or in the jurisdiction in which it was obtained
Proof of a valid negative molecular test taken within 72 hours of your scheduled boarding time
for example, if you’re scheduled to board at 11:00 am on Friday, your test must have been taken any time after 10:59 am on Tuesday
it must be administered or observed by a pharmacy, laboratory, healthcare entity or telehealth online service
the test must be authorized for sale or distribution in Canada or in the jurisdiction in which it was obtained