diff --git a/extract_contours.py b/extract_contours.py
index eb5cbea..5a271f4 100644
--- a/extract_contours.py
+++ b/extract_contours.py
@@ -40,7 +40,7 @@ for beach in beaches:
                     survey = df.loc[(beach, block, profile, date), :]
                     survey = survey.set_index('Chainage')
 
-                    # Reverse survey chainage for interpolation
+                    # Reverse survey chainage so elevation is increasing
                     survey = survey[::-1]
 
                     # Find largest chainage in profile above contour elevation