diff --git a/src/k_kart.c b/src/k_kart.c
index 40d1ff0a2..6bb2be28e 100644
--- a/src/k_kart.c
+++ b/src/k_kart.c
@@ -3445,6 +3445,8 @@ boolean K_WaterRun(mobj_t *mobj)
 
 		case MT_PLAYER:
 		{
+			fixed_t minspeed = 0;
+
 			if (mobj->player == NULL)
 			{
 				return false;
@@ -3455,11 +3457,18 @@ boolean K_WaterRun(mobj_t *mobj)
 				return K_IsHoldingDownTop(mobj->player) == false;
 			}
 
+			minspeed = 2 * K_GetKartSpeed(mobj->player, false, false); // 200%
+
+			if (mobj->player->speed < minspeed / 5) // 40%
+			{
+				return false;
+			}
+
 			if (mobj->player->invincibilitytimer
 				|| mobj->player->sneakertimer
 				|| mobj->player->tiregrease
 				|| mobj->player->flamedash
-				|| mobj->player->speed > 2 * K_GetKartSpeed(mobj->player, false, false))
+				|| mobj->player->speed > minspeed)
 			{
 				return true;
 			}
@@ -10362,6 +10371,9 @@ boolean K_FastFallBounce(player_t *player)
 			}
 		}
 
+		if (player->mo->eflags & MFE_UNDERWATER)
+			bounce = (117 * bounce) / 200;
+
 		S_StartSound(player->mo, sfx_ffbonc);
 		player->mo->momz = bounce * P_MobjFlip(player->mo);
 
diff --git a/src/p_mobj.c b/src/p_mobj.c
index eaa5b058c..250b8b470 100644
--- a/src/p_mobj.c
+++ b/src/p_mobj.c
@@ -3222,14 +3222,15 @@ boolean P_CanRunOnWater(mobj_t *mobj, ffloor_t *rover)
 	// We start water run IF we can step onto it!
 	if (surfDiff <= maxStep && surfDiff >= 0)
 	{
-		if (ourZAng < 0)
+		pslope_t *groundSlope = (flip ? mobj->subsector->sector->c_slope : mobj->subsector->sector->f_slope);
+		if (groundSlope != NULL && groundSlope->zangle != 0)
 		{
 			fixed_t floorheight = flip ? P_GetSectorCeilingZAt(mobj->subsector->sector, mobj->x, mobj->y) : P_GetSectorFloorZAt(mobj->subsector->sector, mobj->x, mobj->y);
 			fixed_t floorDiff = flip ? (floorheight - mobjbottom) : (mobjbottom - floorheight);
 			if (floorDiff <= maxStep && floorDiff >= -maxStep)
 			{
-				// ... but NOT if going down and real floor is in range.
-				// FIXME: Count solid FOFs in this check
+				// ... but NOT if downward-sloping real floor is in range.
+				// FIXME: Count solid FOFs in these checks
 				return false;
 			}
 		}