I appreciate the response, here are the initial steps i did when i first started the map.
I started with a blank map, added the prefab colloseum and filled it with assorted props for a gun game, then deleted the initial flat grid from the blank template to make the arena appear to be floating, and added a custom skybox. It doesnt seem to be any specefic mesh as it happens to walls, trees, bushes, everything at that level. it wont show in the editor, only in game on medium or higher settings.
The shadow effect appears to start at roughly Z: 375, and any flat suface between Z:375-400 Gives the water ripple effect when walking on it.
