diff --git a/vendor/clouds3d.js b/vendor/clouds3d.js
index 6d02357..93aca8c 100644
--- a/vendor/clouds3d.js
+++ b/vendor/clouds3d.js
@@ -136,7 +136,7 @@ var FRAG_SRC = [
         // Camera path: slow drift in X, cruising just above the cloud deck
         // like an airliner cockpit. No dives — we stay above so the
         // deck is always visible below us.
-        'float drift = uTime * uSpeed * 0.45;',
+        'float drift = uTime * uSpeed * 0.12;',
         // Fixed altitude well above the cloud ceiling (y=1.5).
         'float camY = 2.2;',
         'vec3 ro = vec3(0.0, camY, drift);',
@@ -275,9 +275,9 @@ var GROUND_TILE_SIZE = 256;
 // The corridor is aligned with both motion and look direction.
 var GROUND_TRAVEL_COS = 0.0;      // cos(90 deg)
 var GROUND_TRAVEL_SIN = 1.0;      // sin(90 deg)
-var GROUND_CORRIDOR_LONG = 15;    // tiles along the travel direction
+var GROUND_CORRIDOR_LONG = 25;    // tiles along travel direction (~3.5 min of flight at uSpeed=1)
 var GROUND_CORRIDOR_PERP = 5;     // tiles perpendicular to travel
-var GROUND_BUFFER_LONG = 2;       // refetch when this close to forward edge
+var GROUND_BUFFER_LONG = 3;       // refetch when this close to forward edge
 var GROUND_BUFFER_PERP = 1;       // refetch when this close to side edge
 // Passau tile at zoom 11
 var GROUND_BASE_X = 1099;
@@ -522,7 +522,7 @@ window.clouds3dRender = function(target) {
     gl.uniform2f(s.uGroundCenter, centerWorld.x, centerWorld.y);
     gl.uniform2f(s.uGroundSize, GROUND_CORRIDOR_LONG, GROUND_CORRIDOR_PERP);
 
-    var drift = now * speed * 0.45;
+    var drift = now * speed * 0.12;
     if (performance.now() - groundLastCheck > 1500) {
         groundLastCheck = performance.now();
         maybeRefetchGround(drift, drift * 0.7, gl);