The website of Greek Reporter has a piece about a theory which seeks to explain the origin of the name Thule, given by the ancient Greeks to the northern limits of the earth, and identifies it as being Iceland.
The argument seems plausible - after all Iceland is more or less in the right place to be Thule - and the suggestion that the appearance of the southern coast inspired the name also appears reasonable. That said the theory turns upon the original name having been miscopied to emerge as Thule. Thus our old friend scribal error becomes a major player in the story. That and the debatable nature of evidence derived from etymology, must be borne in mind. Even so, as I wrote, the theory looks perfectly reasonable given the geography of the northern Atlantic.
If that is accepted or considered worthy o serious consideration then it can be seen to reinforce the case for early navigation in those northern seas. Such voyages may have left no record or scant record but their feasibility or their memory in legend should not be discounted.
The article can be seen at Greek Discovery of Iceland Supported by Linguistic Evidence