We will be driving from Bergen to Geiranger on Sunday, July 14th. Does this ferry get sold out? Should I pre-purchase the ticket and guess at the departure time?
To me, it looks pretty encouraging that the ferry site does not make a big push for advance reservations. People who do have reservations are only required to show up 15 minutes before departure, so it must not take too long to load them. If you aim for an early time and end up having to wait, there still would be later options on the same day.