In the Dune universe created by Frank Herbert, Guild Navigators or Steersmen are humans, mutated through the consumption of massive amounts of the spice melange, who are able to safely navigate interstellar space in a heighliner using a limited form of prescience. To enable their prescience, Guild Navigators are continuously immersed in highly-concentrated amounts of orange spice gas, which causes their bodies to atrophy and mutate over time, their heads and extremities elongating. The first external sign of melange-induced metabolic change is visible in the eyes, as the drug tints the sclera and iris to a dark shade of blue, called "blue-in-blue" or "the Eyes of Ibad," appearing almost black.

Because the Spacing Guild uses mainly envoys and ambassadors in their dealings, Guild Navigators are historically seldom seen. Although their appearance is a mystery in the original 1965 novel Dune, a Navigator is fully revealed in the first chapter of Dune Messiah (1969). Here, the Guild Navigator Edric is called a "humanoid fish," and described in his tank of spice gas as "an elongated figure, vaguely humanoid with finned feet and hugely fanned membranous hands — a fish in a strange sea." The Navigators' "elongated and repositioned limbs and organs" are noted in Heretics of Dune.

In 1985's Chapterhouse Dune, Lucilla notes that "Navigators were forever bathed in the orange gas of melange, their features often fogged by the vapors," that they possess a "tiny v of a mouth" and "ugly flap of nose" and that "Mouth and nose appeared small on a Navigator's gigantic face with its pulsing temples." She also notes that their mutated voices require translation devices, describing "the singsong ululations of the Navigator's voice with its simultaneous mechtranslation into impersonal Galach."

Similar to 0 things you like: