[Dottore]

You'd have to check the Washington State Ferry Schedule (it's online somewhere) - but I kind of doubt it. There are not that many ferries to Victoria from the San Juan Islands.

Spending just a few hours in Victoria would be frustrating anyway, as there is a fair bit to do and see. If you do overnight in Victoria - I highly recommend the Hotel Magnolia - which is right in the best part of downtown, has brilliant rooms and is spectacular value for money.