Read "Rebels of the Red Planet" by Charles L. Fontenay online for free on Textopian. Full text with search, annotations, highlights, and AI-powered reading aids.
It is a sea, though they call it sand.
They call it sand because it is still and red and dense with grains. They call it sand because the thin wind whips it, and whirls its dusty skim away to the tight horizons of Mars.