Change-fields are areas irradiated with Change on a (semi-)permanent basis. The extremity of the Change-field increases as you approach its centre, like a raging tempest. Nobody has ventured to the centre of a Change-field and returned.
The Threshold is the outer region of a Change-field. One can safely travel in the Threshold for up to four days. It poses the risk of minor Change-burns. There are often rapid weather changes, especially tropical storms that appear in an instant and end just as fast. Home to Chromatic Sirens and unnatural kelp forests that will tangle ships, as well as islands covered in Sea Sheep and groves of Prototaxite fungi.
The Rift is the secondmost region of a Change-field. One can safely travel in the Rift for up to two days. It poses the risk of moderate Change-burns.
Surviving the Rift calls for skilled navigators, and possibly an Iguanid or Terran motor engine. Here, you can find feral Reef Devils who have reverted to their hostile base instincts, and the occasional sea monster. Devils' Reef is in the rift of a Change-field not too far from Odir.
The Eventide is the penultimate region of a Change-field. The Eventide poses the risk of severe Change-burns and grotesque mutations, with practically no safe travel time. It is home to a great deal of leviathans of all shapes and sizes, each of which could wreck a ship in an instant. It also contains Basalt Isles. It's essential to use a Change-field navigation device such as an Omniglyph to successfully traverse these and escape alive.
The Aurora is the innermost region of the Change-field. There is no safe level of exposure to the Aurora, and it presumably carries an extreme risk of severe Change-burns and irreversible mutations of all kinds, if it doesn't immediately kill. Nobody has survived this zone. Here lies the Octeract.