The South African is the ninth homegrown player signing in club history.
The 20-year-old joins Vancouver's MLS roster after started six of his seven appearances with the under-23 squad. He has appeared in five of the team's pre-season matches leading into the 2014 campaign.
He previously served as captain of South African club ASD Cape Town and was called up to South African U20 national team camp in 2011.
"Ethen is a player we've gotten to know very well from his time with the club over the last year," said Whitecaps FC head coach Carl Robinson. "He has a number of qualities, such as his desire, versatility and physicality, that will be valuable to our squad."