I want to book an overnight trip from Alesund to Tronheim including a cabin. I have been to the Hurtigruten site several times and it is nonobvious to me how to book other than a multi day cruise.

- How do I do this?
- How far in advance do bookings open for summer 2018?

I can find the schedule for June 2018 but no booking information. I found this description off FT:

Departure Ålesund is 0930, and it sails via Hjørundfjorden to Trondheim, arriving the next day at 0830. The ship will make a trip into the Hjørundfjord, returning to Ålesund in the afternoon, departing again 1900 in the evening, sailing to Trondheim. So you really will get to see the fjords and the coast. If you go for Hurtigruten, try to stay awake until after the call at Kristiansund late in the evening.