From what I can see the passenger ferry leaves Trondheim at 06.15, arrival at Brekstadt at 07.25, which should give ample time to walk to the base. Return time is 16.00 or 19.00 with Trondheim arrivals at 17.10 or 20.10. These are for the Friday spottersday. The fare looks to be 215NOK each way (about £45 return) and I imagine it will be a nice trip.
However, if planning also to do the airshow on the Saturday the passenger ferry isnt an option as there isnt a morning boat, so it may well have to be a drive that day, which may be problematical in getting a car ferry as I would expect the airshow to draw a bigger crowd.
Does anyone know if there will be additional boats operating on Saturday? it would make sense but I cant find any info on this at present.


Flying displays at Tigermeets are rare as I know, I would go for spotters day on Friday IF I would go. But TBH the participants list is nothing to write home about.