Possible Instrument Navigation of Viking Sailors
It is impossible to imagine how the Viking could cross the waves of the ocean and make it to another continent when the technology was nothing but a stone as their compass. But they did. The Vikings did set sail to reach new land.
There is little evidence showing that the Vikings had used a certain means of navigation. Accordingly, the scholars focused on studying the materials and technology available in the Viking Age.
When it comes to the actual instruments, the Vikings could have made use of water depth, speed, course, and latitude (the height of the sun).
But to be able to navigate land based on those mentioned instruments, that Viking sailor must be extremely experienced. Observations from the ancestors might have been passed down for the offspring. And generations after generations, the Vikings could finally set sail.
Viking sun compass
One more possible means of navigation was the sun compass. The insightful scholars believed that the Viking sun compass functioned very well at sea. It had a vertical pointer on a horizontal surface. Through the say, the pointer would draw shadow on the surface of the compass. Archaeological evidence in Greenland presented the remains of the Viking sun compass. It was a circular disk with carvings that the archaeologists found in Greenland in 1948.
So that was in the time when the sun was visible in the sky. What if the sun was absent because of the clouds?
Viking sunstone appearing in "Vikings" TV Show
The sagas told us about the sunstones. These magical stones would provide the sailors with the directions of the sun behind the clouds. The mineral from which the sunstone could have been made could be a mineral that could polarize the light.