“Flow” by Arlan Andrews Sr. was published in Analog Science Fiction and Fact. Analog published it free to read online as part of the Hugo season.
Rist and Cruthar live with their people in the Tharn’s Lands where the world exists in unending hazy twilight. They make their living by riding icebergs that break off from the greater ice mass to sell them to warmlanders further south. In this story Rist takes his first berg-riding trip to the south, where the sky is blue and the light burns brightly in the sky. They are only meant to take the iceberg as far as the ice broker, but Rist gets the idea to ride the iceberg further south, and so they go on to the strange lands of the south for an adventure. People from different lands have lived separately long enough to gain differentiating racial features, including extreme farsightedness so that none can see things clearly up close in favor of far vision. The people of the Tharn’s Lands used carved figurines for writing, and Rist keeps a journal of everything he does, and everything he learns to share with his family (both on a philosophical level and things that might have applications in their merchant business).