Planet
Oktarion
The eight moons: tides so powerful the sea covers the continents at every turn of the planet, and a whole living world set to that rhythm.

Oktarion has eight moons, and all of them pull on the same ocean. Under that weight the sea rises into two standing bulges — one on the moons’ side, one opposite. The planet turns, and so passes twice a day beneath that weight: at each passage the sea covers the continents for hundreds of kilometres, then withdraws.
The true conjunctions, when all eight moons genuinely align, come only once in some centuries. The Arazians have a word for those days, and no survey of what is left of the coastline afterwards.
The great tide
The rise lasts four hours. The water is seen coming from far off, like a low fast wall, and the landscape disappears. Then the sea stays three hours, and leaves. Whatever grows on Oktarion must therefore endure being drowned twice a day: the plants close like fists and wait.
Living between two seas
No animal of Oktarion is truly terrestrial nor truly marine: they are both. The kaltor, the size of an ox, breathes through gills when the sea is in and through lungs when it has gone. The ammirs dig watertight burrows and seal themselves in at the appointed hour, with a precision even the Arazians cannot explain.