How long is a flight from Vancouver BC to Seoul Korea?
According to orbitz.com, a non-stop flight from Vancouver to Seoul would be about 11 hours 15 minutes long, if you're willing to pay extra for that convenience.
For less cost, a flight from Vancouver to Seattle would be between 54 minutes and 1 hour 6 minutes, then from Seattle to Seoul 11 hours 5 minutes, and there would be a layover in Seattle of 1 to 2 hours. Or your flight could go from Vancouver to Tokyo in 9 hours 45 minutes, then from Tokyo to Seoul in about 2 hours (again with a 1 to 2 hour layover in between).
There are also flights through other places such as China, Taiwan, Los Angeles, and San Francisco, and if you're willing to increase your layover time to 3-6 hours you might even save some money.
Here is an example:
Van (VAN) to Seoul (SEL)
Flight Duration * 14 hours 25 mins * Via Istanbul Ataturk Airport, Istanbul (IST)