Modern-day Norse saga tells of ancient skills and history

Docked in Boston Harbor, the Saga Siglar - a replica of an ancient Viking sailing vessel - looks oddly out of place against the downtown skyline. But this open-hulled wooden ship with its hemp rigging and single square sail proved its worth before arriving here recently after a rough 21/2-month crossing of the North Atlantic.

Expedition leader Ragnar Thorseth sits in the stern of the ship, relaxing for a few minutes in the warm September sun. Sporting a ruddy beard and a striped shirt, he talks about completing the first leg of his unique voyage around the world.

''In the beginning for me (this expedition) was a dream,'' says Mr. Thorseth, a Norwegian adventurer-explorer adept at turning dreams into reality.

On June 17 this year, the Saga Siglar set sail from Sogndal, Norway, to retrace the early Viking sailing routes from Norway to Iceland, Greenland, and North America. The ship, made from Norwegian pine, is a careful reproduction of the same type of vessel used by the Vikings about 1,000 years ago.

Between Greenland and Labrador, the Saga Siglar encountered a fierce storm that threatened to overcome the 57-foot boat. But both the ship and its seven-man crew proved to be seaworthy.

''You have a lot more confidence in the ship when you get through a storm like that,'' says Mr. Thorseth. He also recalls the courage of his 11-year-old son, Erik, who sailed with the crew as far as Newfoundland.

''We were all in our survival suits ready to jump into the life raft if the boat filled in and sunk. There he was in a survival suit that was 10 (times) too big for him. He did very well - he never complained,'' says Mr. Thorseth. ''He really grew up the last two months. It was a great opportunity for us to really get close.''

Mr. Thorseth's plan to sail around the world in a Viking ship was originally sparked during an expedition to the North Atlantic. From 1957 to 1975 he followed the route of Eric the Red and Leif Ericsson to North America in a small , modern Norwegian fishing boat, visiting old Norse settlements along the way.

''What amazed me was how they were able to sail that part of the Atlantic in open boats,'' he says.

As described in Norse sagas, the Vikings used a boat called a knarr to sail the northern seas. Unlike the long, slim boats with dragon figureheads used in battle, the wide-hulled knarr was designed as a deep-sea merchant and cargo ship. Leif Ericsson sailed in a knarr to reach the shores of North America.

In 1959, archaeologists recovered the most well-preserved remains of a knarr to date from Denmark's Roskilde Fjord. When word of the discovery reached Mr. Thorseth, he recalls, ''The idea struck me: Why not sail around the world in one of these boats?''

When he arrived back in Scandinavia, he continues, ''I went down to the Viking Ship Museum in Denmark with my plans and I got a fantastic reception. They wanted to build a replica of the knarr and see how it sailed, but they hadn't been able to raise the money.''

With funding from several corporate sponsors and individuals in Norway, Sweden, Denmark, and the United States, the project began to take shape. Master craftsman Sigurd Bjorkedal, from the famous shipbuilding region of Bjorkedalen, Norway, was chosen to build the replica. From the summer of 1982 to April of 1983 Mr. Bjorkedal and his two sons, Ottar and Jakob, constructed the knarr with the same tools and techniques used by the Vikings.

In the meantime Mr. Thorseth drew on the expertise of scholars at the Viking Ship Museum and experienced sailors in Norway to learn the basics of sailing such a ship. The knarr has a a very shallow draft - about 21/2 feet - and a side rudder that is usually kept stable. Most of the steering is done with the large square sail. For this trip, modern navigational devices such as a compass, radar , and a radio are also on board.

''Before I started I had no experience sailing except as a small boy at home, '' Mr. Thorseth says. ''But my experience in the open sea is wide and long. I like the challenge.''

In the past he has taken a series of expeditions to the Arctic and around Iceland and Greenland. In 1982 he led the first Norwegian expedition to reach the North Pole across ice.

One of the main purposes of the current expedition, called Operation Viking, is to learn as much as possible about the capabilities of the ancient knarrs - how seaworthy they are, what kind of load they can handle, and how fast they can sail.

''When we learn about this ship, we learn more about how it was possible for the Vikings to keep regular sailing routes in the North Atlantic,'' says Mr. Thorseth. Operation Viking is divided into two parts: a tour of Europe that was completed in the summer of 1983 and the retracing of the Viking routes and the trip around the world from 1984 to '86.

''The crossing of the Atlantic has been just great,'' he says. ''Of course, we made it - the boat proved to be good. Its performance surpassed the expectations of most of the scholars. We can sail into the wind with an angle of 50-60 degrees and it can sail 179 nautical miles in 24 hours. For short periods we reached a top speed of 12 knots.''

In addition to gaining scientific knowledge, another purpose of the expedition is to acquaint people with Norwegian history and to dispel the notion that all the Vikings were fierce warriors. According to Mr. Thorseth, many Norsemen were farmers, merchants, and navigators. Most of the Vikings were farmers who left Norway because of a lack of land.

Mr. Thorseth will have many opportunities to share his knowledge as the Saga Siglar makes its way up the Hudson River, through the Great Lakes, and down the Mississippi River, stopping at ports along the way. When the boat sets sail from Florida heading for the Panama Canal and the Pacific Ocean, Mr. Thorseth's whole family - his wife, Kari, and his two sons, Erik and nine-year-old Njaal - will be on board.

Looking back on the trip so far, he says, ''I've been on several expeditions and know about many other people's expeditions. Very often there is a tendency to have conflicts on board after some time. I've been so happy with the guys on this trip. There hasn't been a quarrel - not a bad word. We still have so many things to talk about; it's amazing.

''Everyone contributed equally. They're all so clever. We've had fresh bread or a cake every day even during the storm. They are so professional. So for me as an expedition leader it has been really great. The experience is so special - I can't think of anything better.''