--- a/artifacts/src/main/java/org/dive4elements/river/artifacts/WINFOArtifact.java	Fri Jun 19 17:42:23 2015 +0200
+++ b/artifacts/src/main/java/org/dive4elements/river/artifacts/WINFOArtifact.java	Wed Jun 24 14:07:26 2015 +0200
@@ -258,7 +258,7 @@
             log.debug("'free' calculation (km " + refKm + ")");
         }
         else {
-            Gauge gauge = determineRefGauge(range, river);
+            Gauge gauge = river.determineRefGauge(range, rangeAccess.isRange());
 
             if (gauge == null) {
                 return error(
@@ -730,7 +730,7 @@
             log.debug("range: " + Arrays.toString(range));
         }
 
-        Gauge g = determineRefGauge(range, rangeAccess.getRiver());
+        Gauge g = rangeAccess.getRiver().determineRefGauge(range, rangeAccess.isRange());
         if (g == null) {
             log.warn("no gauge found for km: " + range[0]);
             return null;
@@ -782,36 +782,15 @@
 
 
     /**
-     * Determine reference gauge dependent on direction of calculation
-     * for a range calculation, otherwise dependent on flow direction.
-     */
-    public Gauge determineRefGauge(double[] range, River river) {
-        if (isRange()) {
-            return river.determineGaugeByPosition(
-                range[0],
-                range[0] > range[1]);
-        }
-        else {
-            return river.determineGaugeByPosition(range[0]);
-        }
-    }
-
-    /**
      * Determines the selected mode of distance/range input.
      *
+     * Compatibility wrapper around RangeAccess.
+     *
      * @return true, if the range mode is selected otherwise false.
      */
     public boolean isRange() {
-        StateData mode = getData("ld_mode");
-
-        if (mode == null) {
-            log.warn("No mode location/range chosen. Defaults to range.");
-            return true;
-        }
-
-        String value = (String) mode.getValue();
-
-        return value.equals("distance");
+        RangeAccess rangeAccess = new RangeAccess(this);
+        return rangeAccess.isRange();
     }
 
 

--- a/artifacts/src/main/java/org/dive4elements/river/artifacts/access/RangeAccess.java	Fri Jun 19 17:42:23 2015 +0200
+++ b/artifacts/src/main/java/org/dive4elements/river/artifacts/access/RangeAccess.java	Wed Jun 24 14:07:26 2015 +0200
@@ -72,6 +72,11 @@
         return mode;
     }
 
+    /** Check if the calculation mode is Range. */
+    public boolean isRange() {
+        return getKmRangeMode() == KM_MODE.RANGE;
+    }
+
     /**
      * Return sorted array of locations at which stuff was calculated
      * (from ld_locations data), null if not parameterized this way.

--- a/artifacts/src/main/java/org/dive4elements/river/artifacts/services/MainValuesService.java	Fri Jun 19 17:42:23 2015 +0200
+++ b/artifacts/src/main/java/org/dive4elements/river/artifacts/services/MainValuesService.java	Wed Jun 24 14:07:26 2015 +0200
@@ -32,6 +32,8 @@
 
 import org.dive4elements.river.artifacts.model.RiverFactory;
 
+import static org.dive4elements.river.backend.utils.EpsilonComparator.CMP;
+
 
 /**
  * This service returns the main values of a river's gauge based on the start
@@ -84,7 +86,8 @@
         }
 
         double[] minmax = getRequestedStartEnd(data, river);
-        Gauge gauge = river.determineGauge(minmax[0], minmax[1]);
+        Gauge gauge = river.determineRefGauge(minmax,
+                CMP.compare(minmax[0], minmax[1]) != 0);
 
         if (gauge == null) {
             return error("no gauge found.");

--- a/artifacts/src/main/java/org/dive4elements/river/utils/RiverUtils.java	Fri Jun 19 17:42:23 2015 +0200
+++ b/artifacts/src/main/java/org/dive4elements/river/utils/RiverUtils.java	Wed Jun 24 14:07:26 2015 +0200
@@ -434,37 +434,19 @@
     /**
      * Return the (first) Gauge corresponding to the given location(s) of
      * the artifact.
+     *
+     * This method is left for compatibility. Use river.determineRefGauge()
+     * directly in new code.
+     *
      * @param flys the artifact in question.
-     * @return (First) gauge of locations of river of artifact.
+     * @return Reference / first gauge of locations of river of artifact.
      */
     public static Gauge getGauge(D4EArtifact flys) {
         River river = getRiver(flys);
-
-        if (river == null) {
-            log.debug("no river found");
-            return null;
-        }
-
         RangeAccess rangeAccess = new RangeAccess(flys);
         double[] dist = rangeAccess.getKmRange();
 
-        if (dist == null) {
-            log.debug("no range found");
-            return null;
-        }
-
-        if (log.isDebugEnabled()) {
-            log.debug("Determine gauge for:");
-            log.debug("... river: " + river.getName());
-            log.debug("... distance: " + dist[0] + " - " + dist[1]);
-        }
-
-        Gauge gauge = river.determineGauge(dist[0], dist[1]);
-
-        String name = gauge != null ? gauge.getName() : "'n/a";
-        log.debug("Found gauge: " + name);
-
-        return gauge;
+        return river.determineRefGauge(dist, rangeAccess.isRange());
     }
 
 

--- a/backend/src/main/java/org/dive4elements/river/model/River.java	Fri Jun 19 17:42:23 2015 +0200
+++ b/backend/src/main/java/org/dive4elements/river/model/River.java	Wed Jun 24 14:07:26 2015 +0200
@@ -390,6 +390,21 @@
     }
 
     /**
+     * Determine reference gauge dependent on direction of calculation
+     * for a range calculation, otherwise dependent on flow direction.
+     */
+    public Gauge determineRefGauge(double[] range, boolean isRange) {
+        if (isRange) {
+            return determineGaugeByPosition(
+                range[0],
+                range[0] > range[1]);
+        }
+        else {
+            return determineGaugeByPosition(range[0]);
+        }
+    }
+
+    /**
      * Returns the min and max distance of this river. The first position in the
      * resulting array contains the min distance, the second position the max
      * distance.