To avoid the 3 hrs drive along the I-5 Hwy and possible extended waits at the Peace Arch border crossing, the fastest & best way on how to get from Seattle to Victoria is by ferry.
Please note that any crossing between the USA & Canada whether by plane, vehicle or ferry requires a valid passport.
Visitors often request ferry travel information on the best way to get from Seattle to Victoria Island. Victoria Island is in fact located in the Canadian Arctic - but Victoria BC is located on the southern tip of Vancouver Island. The downtown to downtown ferry trip is approximately 2-3/4 hrs.
There is only one ferry system traveling from downtown Seattle to downtown Victoria. The ferry is a high speed 425 seat passenger-only catamaran. Two seat classes are available on the ferry: standard fare seats and comfort class seats.
If planning a stay in Victoria and to maximize travel dollars, one can secure the cheapest Victoria BC Clipper tickets by booking a combo ferry / hotel package.