The ship docks at 8am, or you are on the street at 8am? If the former, no way... disembarkation formalities will take a couple of hours. If the latter, probably.

A cab ride from Canada Place, where most ships dock, to YVR will take 30 or 40 minutes at that (morning rush) hour. There's no freeway right to the airport, you have to plow south through the downtown area and out through the southern suburbs on stop-light arterials. If you're flying out of Canada you want to be there by 900am or so for a 1030am departure.