diff --git a/src/engine/InterestManagement/HeightMap.java b/src/engine/InterestManagement/HeightMap.java
index edccb593..4bca8037 100644
--- a/src/engine/InterestManagement/HeightMap.java
+++ b/src/engine/InterestManagement/HeightMap.java
@@ -199,28 +199,31 @@ public class HeightMap {
 
     public static float getWorldHeight(Zone currentZone, Vector3fImmutable worldLoc) {
 
-        if (currentZone == null)
-            return 0;
+        Zone heightMapZone;
 
-        currentZone = getNextZoneWithTerrain(currentZone);
+        //  Seafloor is rather flat.
 
         if (currentZone == ZoneManager.getSeaFloor())
-            return currentZone.getAbsY();
+            return currentZone.worldAltitude;
+
+        // Retrieve the next zone with a heightmap attached.
+        // Zones without a heightmap use the next zone up the
+        // tree to calculate heights from.
+
+        heightMapZone = getNextZoneWithTerrain(currentZone);
 
-        HeightMap heightMap = currentZone.getHeightMap();
+        // Transform world loc into zone space coordinate system
 
-        if ((heightMap == null) || (currentZone == ZoneManager.getSeaFloor()))
-            return currentZone.getAbsY();
+        Vector2f zoneLoc = ZoneManager.worldToZoneSpace(worldLoc, heightMapZone);
 
-        Vector2f zoneLoc = ZoneManager.worldToZoneSpace(worldLoc, currentZone);
+        // Interpolate height for this position using pixel array.
 
-        float interaltitude = currentZone.getHeightMap().getInterpolatedTerrainHeight(zoneLoc);
+        float interpolatedTerrainHeight = heightMapZone.getHeightMap().getInterpolatedTerrainHeight(zoneLoc);
 
-        float worldAltitude = currentZone.worldAltitude;
+        // Position returned from Heightmap engine is relative to zone world height
 
-        float realWorldAltitude = interaltitude + worldAltitude;
+        return interpolatedTerrainHeight + heightMapZone.worldAltitude;
 
-        return realWorldAltitude;
     }
 
     public static float getWorldHeight(Vector3fImmutable worldLoc) {