Viking Navigation - How Did They Know Where They Were Going?
The Vikings navigated without a magnetic compass. They kept to the coast where they could, and on the open sea they steered by the sun, by landmarks such as mountains and islands, and by signs of land such as birds and whales, following sailing directions handed down from earlier voyages. A wooden disc from Greenland may be part of a sun compass, though that is disputed, and the “sunstone” for finding the sun through cloud comes from a medieval Icelandic tale; its use at sea is a modern hypothesis.
We live in a time when it is almost impossible to imagine going on a long trip without a good navigation system. Especially when it comes to the destination we are going to for the first time.
And now imagine what a journey in the Viking Age looked like.
We are not talking about going by car from one place to another, but about crossing the open ocean on a Viking ship at a time when even the most ordinary compass was not available. It seems impossible, but since the Vikings were famous sailors, it is clear that they still knew how to find their way.
The Vikings lived in a time when navigation methods were scarce, so they had to learn how to cope without modern navigation instruments.
No map survives from the Viking Age, and there is no sign that sailors used charts. Their knowledge was carried in memory: how long a crossing took, which landmarks to look for, and what the sea looked like near land.
It did not always work, and the sagas tell of ships that lost their way. Still, Norse sailors reached Iceland, Greenland and, around the year 1000, the coast of North America.
It was certainly not easy to set sail on the unknown open sea and expose your ship and crew to the harsh sea waters. However, the courage of the Vikings and the desire for a better life were obviously great enough to overcome the fear of the unknown.
What Led the Vikings to Sea Voyages?
We know that trade was very developed in the Viking era. The Vikings traded with countries across Europe and even Asia. It became clear that travel to certain lands could not be done by land. Therefore, sailing on Viking ships was a fundamental aspect of a successful trade.
Many Scandinavians also crossed the sea in search of land to settle, as the settlers of Iceland and Greenland did. On the other hand, we know that wars were also an integral part of Viking life, making sailing even more necessary.
How Did the Vikings Navigate in the Viking Age?
Much of it is less of a mystery than it seems, because a few medieval texts describe it. They show sailors who read the sun, the coastline, the birds and the whales, and who carried the directions of earlier sailors in their heads.
Whenever they could, Norse sailors followed the coast. The clearest early account comes from Ohthere, a Norwegian from Hålogaland who told King Alfred of Wessex about his voyages around 890, recorded in the Old English Orosius. Sailing north, he kept the empty land to starboard and the open sea to port for three days. The port of Sciringes heal in the south, he said, could not be reached in a month if you camped every night and had a fair wind every day. But Norse settlers also reached Iceland, Greenland and even North America, which meant open-sea crossings far from any known shore.
How long did those crossings actually take? Pick any two harbours on our interactive Viking World Map and its voyage calculator will tell you, with sailing speeds anchored to Ohthere's own 9th-century account.
Landnámabók, the Icelandic Book of Settlements, says that ocean-going sailors in the North had no lodestone in those days. So when Flóki Vilgerðarson set out to find Iceland, he held a great sacrifice and hallowed three ravens to show him the way. The first raven flew back over the stern, the second flew up and came back to the ship, and the third flew ahead over the prow, in the direction where they found land.
The same book preserves sailing directions for the open sea. From Hernar in Norway, near Bergen, a ship should sail always west to Hvarf in Greenland: north of Shetland, so that it is seen only in very clear weather; south of the Faroes, so that the sea stands halfway up the mountainsides; and south of Iceland, close enough to see its birds and whales. Hernar and the southern tip of Greenland lie at about the same latitude, 60 degrees north, so historians read this as latitude sailing: hold one east-west line and check it against landmarks on the way.
Landnámabók also counts crossings in dægr, usually read as spans of twelve hours: seven from Stad in Norway to Horn in east Iceland, four from Snæfellsnes west to Greenland, five from Reykjanes to Ireland. Working out where you are from time, speed and heading is what navigators call dead reckoning, and figures like these are its raw material.
No Viking-Age text describes steering by the stars, though experienced sailors surely knew the night sky. But the sailing season was summer, when nights in the North are short and light, and in the far north of Norway the sun does not set at all in midsummer. That made the sun the main guide.
Sailors could judge direction from where the sun rose and set and from its height at midday. Grænlendinga saga shows how much depended on it: when Bjarni Herjólfsson's ship ran into north winds and fog, the crew did not know where they were going for many days, and only when they saw the sun again could they work out the quarters of the sky. Whether they also carried an instrument to read the sun, a so-called sun compass, is still debated.
What is a Viking Sun Compass & How it Works?
The magnetic compass is first mentioned in Europe in the late 12th century, after the Viking Age. What is called the Viking sun compass today is a modern reconstruction built around one archaeological find. (The other “Viking compass”, the eight-armed Vegvísir stave, comes from post-medieval Icelandic books of magic and was never a navigation tool.)
As reconstructed, the sun compass is a horizontal wooden disk with a vertical pin, the gnomon, in the centre. The gnomon casts a shadow on the disk, and lines marked on the disk show where the tip of the shadow should fall if the ship is on course. The shadow is shortest at midday, when the sun is highest, and grows longer as the sun sinks towards the horizon.
The find behind the idea is a wooden half-disc, about 7 cm across, found during the Danish archaeologist C. L. Vebæk's excavations of 1945–48 at Uunartoq fjord in the Norse Eastern Settlement of Greenland, in early layers older than what was taken to be a Benedictine convent. Its curved edge is cut with triangular notches, and its face carries scratched lines.
In the 1950s the Danish navigation expert Carl V. Sølver read it as a sun compass, a bearing dial with a shadow pin. From the late 1970s the astronomer Curt Roslund and others took two of its lines for curves traced by the tip of the gnomon's shadow. In 2013 a team led from Eötvös University in Budapest suggested in the Proceedings of the Royal Society A that it could also have been used at midday to check latitude, which would help a ship hold its course between Norway and Greenland.
Not everyone accepts this. Only half the disc survives, and other scholars have read it as a toy or a church object: Christian Keller and Arne Christensen suggested a confession disc, used by priests to keep count of confessions, while noting that the known examples are much later. A similar wooden disc from the Viking-Age town of Wolin in Poland has been read as a sun compass too. Both remain possible sun compasses, not proven ones.
And even a working sun compass was useless in cloudy weather.
So, relying exclusively upon the sun would mean that the ship's crew was left to the mercy of the weather because not every day was a sunny day.
What did the Vikings do in situations when fog and dark clouds were above them and the sky couldn't be seen? How did they navigate then?
Often the honest answer is that they drifted and waited. The sagas call this hafvillur, losing one's way at sea. In Eiríks saga rauða, a ship bound for Greenland lost its wind and its bearings, and half of the people aboard died of sickness before it reached land. The sunstone is the other answer people give, and it needs care.
What are Sunstones?
The sunstone, sólarsteinn in Old Norse, is a real word from medieval Iceland, but it is not often mentioned in the sagas. The only text that shows one in use is Rauðúlfs þáttr, a short tale about King Óláfr Haraldsson (St Olaf) preserved in Flateyjarbók and other manuscripts of his saga. Hrafns saga Sveinbjarnarsonar mentions a sunstone given to Hrafn by Bishop Guðmundr Arason in the early 13th century, and sunstones are listed among church and monastery belongings in inventories of the 14th and 15th centuries. All of this comes from the Christian Middle Ages, well after the Viking Age, and none of it mentions a ship.
In the tale, the king stays with a wise farmer, Rauðúlfr, whose son Sigurðr says he can follow the course of the sun and moon and tell the hours of day and night even when he cannot see the heavenly bodies. The next morning it is snowing and there is no clear sky anywhere. Óláfr asks Sigurðr where the sun is, then has the sunstone brought, holds it up, sees where light beams from the stone, and finds that Sigurðr was right. The scene takes place on land, at the farm, not at sea.
The idea that sunstones were navigation tools is modern. In 1967 the Danish archaeologist Thorkild Ramskou suggested that the sólarsteinn could have been a crystal that polarises light, such as cordierite or Iceland spar, the clear form of calcite found in Iceland. Light from the sky is partly polarised in a pattern set by the position of the sun, so a navigator looking through such a crystal and turning it could, in principle, find the direction of a hidden sun. Experiments since then suggest the method can work, but they show what was possible, not what Viking sailors actually did.
Does a Sunstone Really Exist?
As a word and an object, yes: medieval Icelanders owned things they called sunstones. As a Viking navigation tool, there is no proof. No sunstone has been found at a Viking-Age site or on a Viking ship.
The crystal often cited as evidence is much later. In 2002 a block of Iceland spar was found in the wreck of an English ship of Elizabeth I's time that sank off Alderney in the Channel Islands in 1592. It lay close to a pair of navigational dividers, and a French and British team led from the University of Rennes suggested in 2013 that it might have served as an optical compass. Their paper ends with the hope that similar crystals will one day be found in Viking wrecks, graves or settlements.
So the Viking sunstone remains a hypothesis: possible, and tested in modern experiments, but not shown to have been used at sea.
What Can We Say For the End?
Not everything about Viking navigation is a mystery. Ohthere's account and the sailing directions in Landnámabók show how it was done: follow the coast where you can, cross open water on a known heading, count the days, and watch for mountains, birds and whales that tell you where land lies. The instruments are the uncertain part. The Uunartoq disc may be a sun compass, and a sunstone may have been taken to sea, but neither is proven.
These sailors committed themselves to open-sea crossings of several days or longer more than 1000 years ago, and not all of them arrived.
Did they measure the height of the midday sun to keep their latitude, or simply hold a line they knew from experience? Did they read the colour of the water or smell land on the wind? No source tells us, though people who spent their lives at sea surely noticed more than any text records.
Whatever the exact methods, they worked well enough to carry Norse settlers from Norway to Iceland, Greenland and North America.
Until our next meeting,
Skål!
Keep exploring: see the full sweep of Norse history in our Viking history timeline, where these voyages reached in Viking exploration, how the longships were built in all about Viking ships, and what drove the journeys in Vikings as traders, or shop our Viking jewelry collection.
Viking Navigation FAQ
Did the Vikings use a compass to navigate?
No magnetic compass was available to them. Landnámabók says that sailors in the North had no lodestone when Iceland was settled. Norse sailors relied on the sun, coastal landmarks, birds and whales, and sailing directions from earlier voyages. A wooden sun compass may also have been used, but that is disputed.
What was a Viking sun compass?
As reconstructed, a sun compass is a horizontal wooden disk with a vertical pin, or gnomon, whose shadow shows direction, and some researchers think it could also check latitude at midday. The idea rests on a wooden half-disc found in the 1940s at Uunartoq in Norse Greenland. Not all scholars accept that it was a navigation instrument.
Did Vikings really use sunstones to navigate in cloudy weather?
There is no proof. The sunstone (sólarsteinn) appears in Rauðúlfs þáttr, where King Óláfr uses one on land to find the sun on a snowy day, and in later church and monastery inventories. Its use at sea is a modern hypothesis, first put forward by Thorkild Ramskou in 1967. The Iceland spar crystal from the Alderney wreck comes from an English ship that sank in 1592, not a Viking one.
Did the Vikings use maps to navigate?
No map survives from the Viking Age, and there is no evidence that sailors used charts. They carried sailing directions in memory, like those preserved in Landnámabók: how many days a crossing took and which landmarks, birds and whales to look for. Where they could, they sailed along the coast.