WorldAltitude for seafloor set

src/engine/InterestManagement/Terrain.java

@@ -81,7 +81,7 @@ public class Terrain {
         //  Seafloor is rather flat.
 
         if (currentZone == ZoneManager.getSeaFloor())
-            return currentZone.worldAltitude;
+            return currentZone.yOffset;
 
         // Retrieve the next zone with a heightmap attached.
         // Zones without a heightmap use the next zone up the