An Ocean World is not an official Imperial planetological classification, but is a term in common usage among Imperial citizens for those planets whose environments are a single, globe straddling ocean across their entire surfaces, with perhaps only a few small archipelagos of islands serving as the only land masses. Since the term "Ocean World" is not an official Imperial classification of the Administratum but simply a label used to describe the planet's predominant environmental feature, most Ocean Worlds that have been settled by Mankind are officially classified as Civilised Worlds, Feral Worlds or even Death Worlds if the environmental conditions or extant marine biosphere are hostile enough to human life. Ocean Worlds often produce hardy peoples superbly adapted to combat in marine environments and so become prime recruiting grounds for the Imperial Guard when it needs Regiments for amphibious or underwater operations.
Notable Ocean Worlds
|Tyran (destroyed by Hive Fleet Behemoth in 745.M41)||Eastern Fringe||Unknown||Unknown||Unknown||N/A|
|Pearl Moon||Segmentum Obscurus||Calixis Sector||Markayn Marches||Karrik System||3.5 million (humans and Abhumans)|
- Codex: Ultramarines (2nd Edition), pg. 14
- Brothers of the Snake (Novel) by Dan Abnett
- Codex: Tyranids (5th Edition), pp. 8-9