diff --git a/Data-model.md b/Data-model.md
index b0f90a5..ef56dd1 100644
--- a/Data-model.md
+++ b/Data-model.md
@@ -280,6 +280,14 @@ Zones data is stored as an array of objects with `i` not necessary equal to the
 * `lock`: `boolean` - `true` if zone is locked (not affected by regeneration). Optional
 * `hidden`: `boolean` - `true` if zone is hidden (not displayed). Optional
 
+
+## Ice
+Ice data is stored as an array of objects with `i` not necessary equal to the element index, but order of element defines the rendering order and is important. Object structure:
+* `i`: `number` - ice element id. Please note the element with id `0` is a fully valid ice element, not a placeholder
+* `type`: `glacier | iceberg` - ice type
+* `offset`: `[number, number]` - ice position offset in px, optional, only added for manually dragged ice elements
+* `points`: `number[][]` - ice element vertices positions
+
 # Secondary global data
 Secondary data exposed to global space.