maybe ask that on the Victoria or Vancouver forum. A sunday nite is always busy. Lots of Island people come to the mainland and vice versa so I would think getting a reservation will avoid a long line up at the ferry. With a reservation you have to get there 1/2 hr before the sailing so I would allow one hr from downtown just to be safe.

davidgmg is right.

Note that the BC Ferries (between Vancouver and Victoria) sail by the hour or at least every 2 hours. If you miss the first ferry, or if you arrive at the terminal and the next ferry is full, you'll have an hour or two (or more) before the next one rolls in.

Sunday nights generally are busier than other days of the week, so it might be a good idea to make a reservation. While reservations *aren't* necessary, if you don't plan to make one, be prepared to wait.