I have been seeing this meme (or memes with the same claim) repeatedly over the years where claims that “The Vikings used ravens to find land”.
This isn’t the case. We do know a story about one Viking using ravens in that way. In the Book of the Settlers/ Landlamabók is says:
Floki took three ravens with him on the voyage. When he set the first one free it flew back from the stern, but the second raven flew straight up into the air, and then back to the ship, while the third flew straight ahead from the prow, and it was in that direction they found land. (The Book of Settlements: Landnámabók, by Herman Palsson (Translator), Paul Edwards (Translator))
Floki were named Raven-Floki after this event. Therefore, it is true, that the story of someone navigating using ravens did exist in the medieval Icelandic sources. The first problem is if the story is written down long after the event. Landnamabok was probably written in the early 12th century and Floki is supposed to have lived in the 9th century. So there are 200-300 years between the event and the written account of Floki sailing to Iceland. There has been some debate weather the store is inspired by the tale of Noah using doves in the same way in the bible or maybe Floki was inspired by the bible to use ravens in the same way. We may never know.
But what we do know is that the Icelanders named him Raven Floki because he used Ravens in that way, and they would more than indicate that it wasn’t a standard way of navigating in the Viking age.
They did use their knowledge of nature as part of their navigation. It’s clear that Viking age sailors knew that the fauna changed when you came close to land and that clouds form over land in the summertime. If you wish to learn more about Viking age Navigation, then I would suggest that you read these articles from The Viking Ship Museum in Roskilde, Denmark:
Nature and sense navigation: https://www.vikingeskibsmuseet.dk/en/professions/education/knowledge-of-sailing/nature-and-sense-navigation
Instrument navigation in the Viking Age?: https://www.vikingeskibsmuseet.dk/en/professions/education/knowledge-of-sailing/instrument-navigation-in-the-viking-age
It is true that some Viking armies/kings used a banner with a raven on it, but that probably had more to do with Ravens being a symbol of Odin who had two ravens named Hugin and Munin. There is a short article about the banner at Viking Answer Lady http://www.vikinganswerlady.com/banners.shtml