From Vancouver, it is a half hour drive to Horseshoe Bay where you would await the arrival of the first ferry. The first ferry ride is a rough 40 minutes from Horseshoe Bay to Langdale.
From Langdale, you would have to drive to the other side of the island and wait for the arrival of the second ferry. The second ferry is a longer 50 minutes ride from Earls Cover to Saltery Bay. Finally, from Saltery Bay you would drive to Powell River.
source: http://www.goodfoodandtravel.com/powell-river
