If there is no rule entitled “Turns” then add a rule entitled “Tectonics” as follows:

Each Island may be Rising, Falling, or neither, defaulting to neither, and tracked on the Great Sea page of the wiki. As a Daily Action, an Island may change its status to either Rising or Falling.

If there is a rule entitled “Turns” then instead add a rule entitled “Tectonics” as follows:

If an Island’s Turn Timer is an even number, then that Island is Rising. If an Island’s Turn Timer is an odd number, then that Island is Falling. Otherwise, it is neither Rising nor Falling.