Well, well, live and learn.
I've looked at Google Maps and I now see what they have done with "the old left turn" to get you onto the highway northbound. You can indeed "make a left turn onto the highway to Whistler."
Here is the google maps satellite view from "Marine Drive and Horseshoe Bay Drive" (renamed from the old Hwy 99) to the flyover near Pascoe Road that accesses the current Hwy 99.)
Zoom in accordingly to see the details.
Thank you so much Dave, for not only driving HB to northbound 99 but also reporting here.
However, these directions do not work for people who are travelling from Lighthouse Park or HB to catch a ferry. They will need to go to Exit 4 and turn around in order to be able to access the ferry fare booths.
Edited: 1:13 pm, June 22, 2012