diff --git a/NCPPlugin/src/main/java/fr/neatmonster/nocheatplus/checks/moving/MediumLiftOff.java b/NCPPlugin/src/main/java/fr/neatmonster/nocheatplus/checks/moving/MediumLiftOff.java
new file mode 100644
index 00000000..ae458648
--- /dev/null
+++ b/NCPPlugin/src/main/java/fr/neatmonster/nocheatplus/checks/moving/MediumLiftOff.java
@@ -0,0 +1,17 @@
+package fr.neatmonster.nocheatplus.checks.moving;
+
+/**
+ * This is for tracking what medium a player has been in before lift-off.
+ * @author mc_dev
+ *
+ */
+public enum MediumLiftOff {
+	/** Ordinary ground, normal jumping. */
+	GROUND,
+	/** 
+	 * Used for reduced jumping height. Until known better this is used for fluids, cobweb.
+	 */
+	LIMIT_JUMP,
+	
+	// TODO: Might add NO_JUMP (web?).
+}
diff --git a/NCPPlugin/src/main/java/fr/neatmonster/nocheatplus/checks/moving/MovingData.java b/NCPPlugin/src/main/java/fr/neatmonster/nocheatplus/checks/moving/MovingData.java
index a9801618..96ef33a2 100644
--- a/NCPPlugin/src/main/java/fr/neatmonster/nocheatplus/checks/moving/MovingData.java
+++ b/NCPPlugin/src/main/java/fr/neatmonster/nocheatplus/checks/moving/MovingData.java
@@ -69,6 +69,11 @@ public class MovingData extends ACheckData {
     	playersMap.clear();
     }
     
+    /**
+     * Assume the player has to move on ground or so to lift off. TODO: Test, might be better ground.
+     */
+    private static final MediumLiftOff defaultMediumLiftOff = MediumLiftOff.LIMIT_JUMP;
+    
     // Violation levels.
     public double         creativeFlyVL            = 0D;
     public double         morePacketsVL            = 0D;
@@ -90,6 +95,7 @@ public class MovingData extends ACheckData {
     public double 		  toX = Double.MAX_VALUE, toY, toZ;
     /** To/from was ground or web or assumed to be etc. */
     public boolean		  toWasReset, fromWasReset;
+    public MediumLiftOff  mediumLiftOff = defaultMediumLiftOff;
 
     // Data of the creative check.
     public boolean        creativeFlyPreviousRefused;
@@ -165,6 +171,7 @@ public class MovingData extends ACheckData {
 		toWasReset = fromWasReset = false; // TODO: true maybe
 		sfHoverTicks = -1;
 		sfDirty = false;
+		mediumLiftOff = defaultMediumLiftOff;
 	}
 
 	/**
@@ -192,7 +199,32 @@ public class MovingData extends ACheckData {
 		toWasReset = fromWasReset = false; // TODO: true maybe
 		sfHoverTicks = -1;
 		sfDirty = false;
+		mediumLiftOff = defaultMediumLiftOff;
 	}
+	
+    /**
+     * Just reset the "last locations" references.
+     * @param loc
+     */
+    public void resetPositions(final Location loc){
+        if (loc == null) resetPositions(Double.MAX_VALUE, 0, 0);
+        else resetPositions(loc.getX(), loc.getY(), loc.getZ());
+    }
+
+    /**
+     * Just reset the "last locations" references.
+     * @param x
+     * @param y
+     * @param z
+     */
+    public void resetPositions(final double x, final double y, final double z) {
+        fromX = toX = x;
+        fromY = toY = y;
+        fromZ = toZ = z;
+        sfLastYDist = Double.MAX_VALUE;
+        sfDirty = false;
+        mediumLiftOff = defaultMediumLiftOff;
+    }
 
 	/**
 	 * Clear accounting data.
@@ -223,29 +255,6 @@ public class MovingData extends ACheckData {
         noFallSkipAirCheck = false;
     }
     
-    /**
-     * Just reset the "last locations" references.
-     * @param loc
-     */
-    public void resetPositions(final Location loc){
-        if (loc == null) resetPositions(Double.MAX_VALUE, 0, 0);
-        else resetPositions(loc.getX(), loc.getY(), loc.getZ());
-    }
-
-    /**
-     * Just reset the "last locations" references.
-     * @param x
-     * @param y
-     * @param z
-     */
-    public void resetPositions(final double x, final double y, final double z) {
-        fromX = toX = x;
-        fromY = toY = y;
-        fromZ = toZ = z;
-        sfLastYDist = Double.MAX_VALUE;
-        sfDirty = false;
-    }
-    
     /**
      * Convenience method.
      * @param loc
diff --git a/NCPPlugin/src/main/java/fr/neatmonster/nocheatplus/checks/moving/SurvivalFly.java b/NCPPlugin/src/main/java/fr/neatmonster/nocheatplus/checks/moving/SurvivalFly.java
index 638368c0..8d32543e 100644
--- a/NCPPlugin/src/main/java/fr/neatmonster/nocheatplus/checks/moving/SurvivalFly.java
+++ b/NCPPlugin/src/main/java/fr/neatmonster/nocheatplus/checks/moving/SurvivalFly.java
@@ -277,8 +277,11 @@ public class SurvivalFly extends Check {
         else{
         	// Check traveled y-distance, orientation is air + jumping + velocity (as far as it gets).
         	vAllowedDistance = (!(fromOnGround || data.noFallAssumeGround) && !toOnGround ? 1.45D : 1.35D) + data.verticalFreedom;
-        	final int maxJumpPhase;
-            if (data.jumpAmplifier > 0){
+        	int maxJumpPhase;
+            if (data.mediumLiftOff == MediumLiftOff.LIMIT_JUMP){
+            	maxJumpPhase = 3;
+            }
+            else if (data.jumpAmplifier > 0){
                 vAllowedDistance += 0.5 + data.jumpAmplifier - 1.0;
                 maxJumpPhase = (int) (9 + (data.jumpAmplifier - 1.0) * 6);
             }
@@ -340,6 +343,27 @@ public class SurvivalFly extends Check {
         }
 		
 		//  Set data for normal move or violation without cancel (cancel would have returned above)
+        
+		// Check lift-off medium.
+		// TODO: Web might be NO_JUMP !
+		if (to.isInLiquid() || to.isInWeb()){
+			data.mediumLiftOff = MediumLiftOff.LIMIT_JUMP;
+		}
+		else if (resetTo){
+			// TODO: This might allow jumping on vines etc., but should do for the moment.
+			data.mediumLiftOff = MediumLiftOff.GROUND;
+		}
+		else if (from.isInLiquid() || from.isInWeb()){
+			data.mediumLiftOff = MediumLiftOff.LIMIT_JUMP;
+		}
+		else if (resetFrom || data.noFallAssumeGround){
+			// TODO: Where exactly to put noFallAssumeGround ?
+			data.mediumLiftOff = MediumLiftOff.GROUND;
+		}
+		else{
+			// Keep medium.
+			// TODO: Is above stairs ?
+		}
 		
         // Apply reset conditions.
         data.toWasReset = resetTo || data.noFallAssumeGround;