diff --git a/src/navigator.js b/src/navigator.js
index abce42d4..09213511 100644
--- a/src/navigator.js
+++ b/src/navigator.js
@@ -443,8 +443,37 @@ function onCanvasClick( event ) {
  * @function
  */
 function onCanvasDrag( event ) {
-    if ( this.viewer.viewport ) {
-        if( !this.panHorizontal ){
+    var canvasDragEventArgs = {
+      tracker: event.eventSource,
+      position: event.position,
+      delta: event.delta,
+      speed: event.speed,
+      direction: event.direction,
+      shift: event.shift,
+      originalEvent: event.originalEvent,
+      preventDefaultAction: event.preventDefaultAction
+    };
+    /**
+     * Raised when a drag event occurs on the {@link OpenSeadragon.Viewer#navigator} element.
+     *
+     * @event navigator-drag
+     * @memberof OpenSeadragon.Viewer
+     * @type {object}
+     * @property {OpenSeadragon.Viewer} eventSource - A reference to the Viewer which raised this event.
+     * @property {OpenSeadragon.MouseTracker} tracker - A reference to the MouseTracker which originated this event.
+     * @property {OpenSeadragon.Point} position - The position of the event relative to the tracked element.
+     * @property {OpenSeadragon.Point} delta - The x,y components of the difference between start drag and end drag.
+     * @property {Number} speed - Current computed speed, in pixels per second.
+     * @property {Number} direction - Current computed direction, expressed as an angle counterclockwise relative to the positive X axis (-pi to pi, in radians). Only valid if speed > 0.
+     * @property {Boolean} shift - True if the shift key was pressed during this event.
+     * @property {Object} originalEvent - The original DOM event.
+     * @property {?Object} userData - Arbitrary subscriber-defined object.
+     * @property {Boolean} preventDefaultAction - Set to true to prevent default click to zoom behaviour. Default: false.
+     */
+     this.viewer.raiseEvent('navigator-drag', canvasDragEventArgs);
+
+     if ( !canvasDragEventArgs.preventDefaultAction && this.viewer.viewport ) {
+       if( !this.panHorizontal ){
             event.delta.x = 0;
         }
         if( !this.panVertical ){