diff --git a/index.html b/index.html
index 2a8b4e8c..8243ebb9 100644
--- a/index.html
+++ b/index.html
@@ -1369,8 +1369,8 @@
           <button id="addMarker" data-tip="Click on map to place a marker. Hold Shift to add multiple. Shortcut: Shift + 5">Marker</button>
         </div>
 
+        <p>Click to create a new map:</p>
         <div id="addFeature">
-          <p>Click to create a new map:</p>
           <button id="openSubmapOptions" data-tip="Click to generate new (sub)map from the current viewport" onclick="openSubmapOptions()">Submap</button>
         </div>
       </div>
diff --git a/main.js b/main.js
index 1645e5ab..8d5f55ef 100644
--- a/main.js
+++ b/main.js
@@ -1715,7 +1715,7 @@ function addZones(number = 1) {
           queue.push(e);
         });
       } catch (er) {
-        console.log('WTF: ', q, cellsArray);
+        console.error('Error in rebel generation: ', q, cellsArray);
         throw er;
       }
     }
diff --git a/modules/submap.js b/modules/submap.js
index 403ca275..ada728ab 100644
--- a/modules/submap.js
+++ b/modules/submap.js
@@ -5,7 +5,7 @@ Experimental submaping module
 
 window.Submap = (function () {
   function resample(parentMap, projection, options) {
-    // generate new map based on (resampling) existing one (parentMap)
+    // generate new map based on an existing one (resampling parentMap)
     // parentMap: {seed, grid, pack} from original map
     // projection: map function from old to new coordinates or backwards
     //  prj(x,y,direction:bool) -> [x',y']
@@ -24,7 +24,6 @@ window.Submap = (function () {
     applyMapSize();
     placePoints();
     calculateVoronoi(grid, grid.points);
-
     drawScaleBar();
 
     const resampler = (points, qtree, f) => {
@@ -43,13 +42,14 @@ window.Submap = (function () {
     grid.cells.prec = new Int8Array(n); // precipitation
 
     const gridCells = parentMap.grid.cells;
-    const forwardGridMap = parentMap.grid.points.map(_=>[]); // old -> [newcelllist]
+    // build cache old -> [newcelllist]
+    const forwardGridMap = parentMap.grid.points.map(_=>[]);
     resampler(grid.points, parentMap.pack.cells.q, (id, oldid) => {
-      const cid = parentMap.pack.cells.g[oldid]
+      const cid = parentMap.pack.cells.g[oldid];
       grid.cells.h[id] = gridCells.h[cid];
       grid.cells.temp[id] = gridCells.temp[cid];
       grid.cells.prec[id] = gridCells.prec[cid];
-      if (options.depressRivers) forwardGridMap[oldid].push(id);
+      if (options.depressRivers) forwardGridMap[cid].push(id);
     })
     // TODO: add smooth/noise function for h, temp, prec n times
 
@@ -62,9 +62,12 @@ window.Submap = (function () {
 
       // and erode riverbeds
       parentMap.pack.rivers.forEach(r =>
-        r.cells.forEach(oldc => {
+        r.cells.forEach(oldpc => {
+          if (oldpc < 0) return; // ignore out of map marker (-1)
+          const oldc = parentMap.pack.cells.g[oldpc];
           const targetCells = forwardGridMap[oldc];
-          if (!targetCells) throw "TargetCell shouldn't be empty.";
+          if (!targetCells)
+            throw "TargetCell shouldn't be empty.";
           targetCells.forEach(c => {
             if (grid.cells.t[c]<1) return;
             rbeds[c] = 1;
@@ -79,12 +82,14 @@ window.Submap = (function () {
     }
 
     markupGridOcean();
-    if (options.addLakesInDepressions)
+    // Warning: addLakesInDeepDepressions can be very slow!
+    if (options.addLakesInDepressions) {
       addLakesInDeepDepressions();
-    // openNearSeaLakes();
+      openNearSeaLakes();
+    }
+
     OceanLayers();
-    // defineMapSize(); // not needed (not random)
-    // TODO: update UI inputs before calculating according to new boundaries.
+
     calculateMapCoordinates();
     // calculateTemperatures();
     // generatePrecipitation();
@@ -92,7 +97,6 @@ window.Submap = (function () {
     reGraph();
 
     // remove misclassified cells
-
     stage("Define coastline.")
     drawCoastline();
 
diff --git a/modules/ui/submap.js b/modules/ui/submap.js
index b9331987..4dd62260 100644
--- a/modules/ui/submap.js
+++ b/modules/ui/submap.js
@@ -19,14 +19,15 @@ const generateSubmap = debounce(async function () {
 
   WARN && console.warn("Resampling current map");
   closeDialogs("#worldConfigurator, #options3d");
+  const checked = id => Boolean(document.getElementById(id).checked)
   const settings = {
-    promoteTown: Boolean(document.getElementById("submapPromoteTown").checked),
-    depressRivers: Boolean(document.getElementById("submapDepressRivers").checked),
-    copyBurgs: Boolean(document.getElementById("submapCopyBurgs").checked),
-    addLakesInDepressions: Boolean(document.getElementById("submapAddLakeInDepression").checked),
-    addMilitary: Boolean(document.getElementById("submapAddMilitary").checked),
-    addMarkers: Boolean(document.getElementById("submapAddMarkers").checked),
-    addZones: Boolean(document.getElementById("submapAddZones").checked),
+    promoteTown: checked("submapPromoteTown"),
+    depressRivers: checked("submapDepressRivers"),
+    copyBurgs: checked("submapCopyBurgs"),
+    addLakesInDepressions: checked("submapAddLakeInDepression"),
+    addMilitary: checked("submapAddMilitary"),
+    addMarkers: checked("submapAddMarkers"),
+    addZones: checked("submapAddZones"),
   }
 
   // Create projection func from current zoom extents
@@ -37,6 +38,16 @@ const generateSubmap = debounce(async function () {
       : [(x-x0) * graphWidth / (x1-x0),  (y-y0) * graphHeight / (y1-y0)];
   }
 
+  // converting map position on the planet
+  const mapSizeOutput = document.getElementById("mapSizeOutput");
+  const latitudeOutput = document.getElementById("latitudeOutput");
+  const latN = 90 - (180 - mapSizeInput.value / 100 * 180) * latitudeOutput.value / 100;
+  const newLatN = latN - y0 / graphHeight * mapSizeOutput.value * 180 / 100;
+  mapSizeOutput.value /= scale;
+  latitudeOutput.value =  (90 - newLatN) / (180 - mapSizeOutput.value / 100 * 180) * 100;
+  document.getElementById("mapSizeInput").value = mapSizeOutput.value;
+  document.getElementById("latitudeInput").value = latitudeOutput.value;
+
   // fix scale
   distanceScale = distanceScaleInput.value = distanceScaleOutput.value = distanceScaleOutput.value / scale;
   populationRate = populationRateInput.value = populationRateOutput.value = populationRateOutput.value / scale;