diff --git a/index.php b/index.php
index 0eddbf0..217b39e 100755
--- a/index.php
+++ b/index.php
@@ -177,6 +177,7 @@
             <select name="units" onchange="setUnits(this.options[this.selectedIndex].value);">
               <option value="metric"<?= (uConfig::$units == "metric") ? " selected" : "" ?>><?= $lang["metric"] ?></option>
               <option value="imperial"<?= (uConfig::$units == "imperial") ? " selected" : "" ?>><?= $lang["imperial"] ?></option>
+              <option value="nautical"<?= (uConfig::$units == "nautical") ? " selected" : "" ?>><?= $lang["nautical"] ?></option>
             </select>
           </form>
         </div>
diff --git a/js/main.js b/js/main.js
index f2b6f80..98ba5b0 100755
--- a/js/main.js
+++ b/js/main.js
@@ -25,6 +25,13 @@ if (units == 'imperial') {
   unit_m = 'ft';
   factor_km = 0.62; // to miles
   unit_km = 'mi';
+} else if (units == 'nautical') {
+  factor_kmh = 0.54; //to knots
+  unit_kmh = 'kt';
+  factor_m = 1; //
+  unit_m = 'm';
+  factor_km = 0.54; // to nautical miles
+  unit_km = 'nm';
 } else {
   factor_kmh = 1;
   unit_kmh = 'km/h';
diff --git a/lang/de.php b/lang/de.php
index 56686a1..8db4379 100644
--- a/lang/de.php
+++ b/lang/de.php
@@ -48,6 +48,7 @@ $lang["api"] = "Karten API";
 $lang["units"] = "Maßsystem";
 $lang["metric"] = "Metrisches";
 $lang["imperial"] = "Angloamerikanisches";
+$lang["nautical"] = "Nautisch";
 $lang["adminmenu"] = "Verwaltung";
 
 ?>
diff --git a/lang/en.php b/lang/en.php
index 8e24016..e01c333 100644
--- a/lang/en.php
+++ b/lang/en.php
@@ -77,6 +77,7 @@ $lang["api"] = "Map API";
 $lang["units"] = "Units";
 $lang["metric"] = "Metric";
 $lang["imperial"] = "Imperial/US";
+$lang["nautical"] = "Nautical";
 $lang["adminmenu"] = "Administration";
 $lang["passwordrepeat"] = "Repeat password";
 $lang["passwordenter"] = "Enter password";