diff --git a/webassets/js/map.js b/webassets/js/map.js
index b4923b8..367df35 100644
--- a/webassets/js/map.js
+++ b/webassets/js/map.js
@@ -29,12 +29,18 @@ function buildQueryString() {
 function updateMap() {
     // Clear existing content
     markersLayer.clearLayers();
-    // Make new markers for all spots with a good location
+
+    // Make new markers for all spots with a good location, not QRT, and not a duplicate spot within the data set.
+    var callsAlreadyDisplayed = [];
     spots.forEach(function (s) {
-        if (s["dx_location_good"]) {
-            let m = L.marker([s["dx_latitude"], s["dx_longitude"]], {icon: getIcon(s)});
-            m.bindPopup(getTooltipText(s));
-            markersLayer.addLayer(m);
+        if (s["dx_location_good"] && (s["qrt"] == null || s["qrt"] == false)) {
+            if (!callsAlreadyDisplayed.includes(s["dx_call"])) {
+                // OK, create the marker
+                let m = L.marker([s["dx_latitude"], s["dx_longitude"]], {icon: getIcon(s)});
+                m.bindPopup(getTooltipText(s));
+                markersLayer.addLayer(m);
+            }
+            callsAlreadyDisplayed.push(s["dx_call"]);
         }
     });
 }