Sand seas (great deserts, sea of dunes) are vast expanses of sandy desert, often found in fantasy and science fiction worlds, that function more like seas or oceans. There may be boat-like vessels that transit these desert seas, either relying on wind power to push them through the sand or hovering above it using some form of magic or future technology. Sand seas usually also have there own ‘islands,’ though these typically come in the form of rocky mesas, high plateaus, walled cities, or oases. Sand seas are a similar element to grass seas. They may be subject to massive sandstorms. They may have their own leviathans, often in the form of sandworms. Their ‘coasts’ may be mountain ranges, or high plateaus.

When designing sand seas, worldbuilders often adapt oceanic and suboceanic elements to a desert environment. This involves taking elements such as whirlpools and shipwrecks and reimagining them in the context of the desert.

Do pirates sail the sand seas of your world? If there are trade routes they may.