One such documentary attempted to see if the techniques described in the Norse Sagas, such as reading the sea, stars and the movements of sea birds could have enabled the Vikings to find their way at sea. The voyage also wanted to see if it was possible to navigate with the aid of a "sun-compass". This device was basically a wooden disk with a central pin, and a curved line drawn on it's surface, representing the movement of the sun during the voyage, the idea being that if the tip of the shadow of the central pin stays on the curved line, then the ship is on course!

Another objective of the voyage was to test if it was feasible to attempt a portage, that is the dragging overland of a Viking ship, across 100 metres of the Shetland Isles, from the North Sea into the Atlantic. This would have presented the Viking sailors with the advantage of being able to avoid a potentially hazardous journey around the top of Shetland, as well as a considerable saving of time.

The ship the crew sailed, named "Borgundknarren", was a replica of a type of Viking trading vessel known as a knarr, which was based on one of the vessels in the Roskilde Viking Ship museum in Denmark. Skippering the Norwegian crew was celebrated sailor Sir Robin Knox-Johnston. Also on board was Tinna Damgaard-Sorensen, director of the Viking ship museum in Roskilde, and David McCullough, an expert on Viking age portage routes. The ship left Bergen on a wonderful Nordic summer's night - it was midnight and still quite light. Knox-Johnston was very enthusiastic throughout the whole voyage about the knarr's performance, handling and simple, robust design.

During the voyage the crew encountered less than favourable weather conditions, and so had to resort to 20th century technology - charts, magnetic compasses, satellite navigation and a diesel engine! As Knox-Johnston said, "what would the Vikings have done...?" They felt justified in their "cheating" though, as they were determined to get to Shetland to test the portage theories, and right up until the weather turned against them they had more than proved that together the sun-compass and the other ancient techniques were more than adequate to keep the knarr on course.

The ship arrived at Shetland 2 days after leaving Bergen. The portage at Shetland was to be over Mavis Grind, some 2 metres higher than in the Viking age. The ship was to be hauled out of the water with a rope fastened to an iron bar slotted through a hole in the keel, but first the 3 tons (!) of the ballast, cargo and the decking had to be removed. On the first attempt the iron bar snapped. The crew then attempted the portage with the rope itself threaded through the hole in the keel, but it sliced through the keel like a hot knife through butter! Time for a quick spot of keel repair work.

A local expert then recommended wrapping the rope right around the boat. Interestingly enough, the local expert had a strong Yorkshire accent! This suggestion worked, and soon the boat was being dragged from the sea on logs greased with cod livers. It was amazing to see a local force of about 70 people, most of whom looked like the descendants of the Viking men who once did this for real, man-handle the knarr from the North Sea and then deposit it into the Atlantic, some 100 metres away!

The entire operation took just 2 hours, but the overall opinion was that for a heavily laden knarr it was simply too much trouble, and that all things considered they would have been better off waiting until weather conditions were favourable to sail around the top of Shetland. The crew were still upbeat, as they had at least proved that such a portage was feasible and probably a desirable option for a lighter warship.

All in all, this was an excellent look at the sea-faring life of the Vikings. There was none of the normal stereotypes present that normally get wheeled out when the Viking age is discussed - horned helmets, furry boots, rape and pillage were nowhere to be seen. The film also presented evidence from Shetland that helped dispel the "marauding savage" notion, suggesting from archaeological work done by Bradford University on Shetland, that Viking settlers on Shetland had peacefully co-existed with the indigenous Pict population. In this documentary we were treated to a very sympathetic view of the Vikings as accomplished ship builders, sailors and traders.

Our only minor quibble was that the television subtitles (on in case our two-year old decided to start shouting!) at one point said the crew were speaking Danish, when they were in fact speaking Nynorsk.

"Borgundknarren" gets a big thumbs-uppy "Raven and Rose" rating of 9 out of 10.