Update to world altitude calculation

src/engine/gameManager/ZoneManager.java

@@ -459,15 +459,21 @@ public enum ZoneManager {
 
         float worldAlttitude = MBServerStatics.SEA_FLOOR_ALTITUDE;
 
-        if (getSeaFloor().getObjectUUID() == zone.getObjectUUID()) {
+
+        // Seafloor
+
+        if (zone.getParent() == null) {
             return worldAlttitude;
         }
 
         Zone parentZone = zone.getParent();
 
-        if (getSeaFloor().getObjectUUID() == parentZone.getObjectUUID()) {
+        // Child of seafloor
+
+        if (parentZone.getParent() == null)
             return worldAlttitude + zone.getYCoord();
-        }
+
+        // return height from heightmap engine at zone location
 
         worldAlttitude = HeightMap.getWorldHeight(parentZone, zone.getLoc());