diff --git a/python/packages/nisar/static/water_mask.py b/python/packages/nisar/static/water_mask.py
index 5fbb42e63..6de9e40fa 100644
--- a/python/packages/nisar/static/water_mask.py
+++ b/python/packages/nisar/static/water_mask.py
@@ -19,8 +19,8 @@ def binarize_nisar_water_mask(water_distance: ArrayLike) -> np.ndarray:
     ----------
     water_distance : array_like
         The input water distance map, in the format specified by the NISAR Water Mask
-        Product Specification\ [1]_. A value of 0 indicates a water pixel. A value of
-        255 represents a no-data (invalid) pixel. Values in 1-200 represent non-water
+        Product Specification\ [1]_. A value of 0 indicates a not-water pixel. A value
+        of 255 represents a no-data (invalid) pixel. Values in 1-200 represent water
         pixels.
 
     Returns
@@ -37,7 +37,7 @@ def binarize_nisar_water_mask(water_distance: ArrayLike) -> np.ndarray:
 
     # Compute a binary mask where the value 1 represents (ocean or inland) water pixels
     # and the value 0 represents non-water pixels.
-    water = water_distance == 0
+    water = (water_distance >= 1) & (water_distance <= 200)
 
     # Get a binary mask of invalid pixels (i.e. pixels whose value is equal to the fill
     # value of 255).
@@ -102,8 +102,8 @@ def binarize_and_reproject_water_mask(
     water_distance_raster_file : path-like
         The file path or name of the input water distance map file. It must be a
         GDAL-compatible raster file in the format specified by the NISAR Water Mask
-        Product Specification\ [1]_. A value of 0 indicates a water pixel. A value of
-        255 represents a no-data (invalid) pixel. Values in 1-200 represent non-water
+        Product Specification\ [1]_. A value of 0 indicates a not-water pixel. A value
+        of 255 represents a no-data (invalid) pixel. Values in 1-200 represent water
         pixels.
     geo_grid : isce3.product.GeoGridParameters
         The output geocoded coordinate grid to re-project the water mask onto.
diff --git a/share/nisar/defaults/static.yaml b/share/nisar/defaults/static.yaml
index 6d61d965a..9eaade8ec 100644
--- a/share/nisar/defaults/static.yaml
+++ b/share/nisar/defaults/static.yaml
@@ -12,7 +12,9 @@ runconfig:
       # [REQUIRED] File path or URL of the input water mask raster file.
       # Must be an existing file in a GDAL-compatible raster format that spans the
       # region of interest and conforms to the NISAR Water Mask Product Specification
-      # (JPL D-107710).
+      # (JPL D-107710), where a value of 0 indicates a not-water pixel, a value
+      # of 255 represents a no-data (invalid) pixel, and values in 1-200 represent
+      # water pixels.
       water_mask_raster_file:
       # [REQUIRED] Path to the input orbit ephemeris XML file.
       # Must be an existing XML file conforming to the NISAR Orbit Ephemeris Product
diff --git a/tests/python/packages/nisar/static/water_mask.py b/tests/python/packages/nisar/static/water_mask.py
index 117d1a744..642d822ed 100644
--- a/tests/python/packages/nisar/static/water_mask.py
+++ b/tests/python/packages/nisar/static/water_mask.py
@@ -9,14 +9,14 @@
 
 
 def test_binarize_nisar_water_mask():
-    # Create three arrays of water pixels (filled with zeros), non-water pixels (filled
+    # Create three arrays of non-water pixels (filled with zeros), water pixels (filled
     # with values in range [1, 200]), and invalid pixels (filled with 255).
-    water = np.zeros((20, 10), dtype=np.uint8)
-    nonwater = np.arange(1, 201, dtype=np.uint8).reshape(20, 10)
+    nonwater = np.zeros((20, 10), dtype=np.uint8)
+    water = np.arange(1, 201, dtype=np.uint8).reshape(20, 10)
     invalid = np.full((20, 10), fill_value=255, dtype=np.uint8)
 
     # Concatenate the three arrays into a single 20x30 array.
-    water_distance = np.concatenate([water, nonwater, invalid], axis=1)
+    water_distance = np.concatenate([nonwater, water, invalid], axis=1)
 
     # Convert the water distance map into a binary water mask
     water_mask = binarize_nisar_water_mask(water_distance)
@@ -25,8 +25,8 @@ def test_binarize_nisar_water_mask():
     assert water_mask.dtype == np.uint8
 
     # Check the mask values.
-    np.testing.assert_equal(water_mask[:, :10], 1)
-    np.testing.assert_equal(water_mask[:, 10:20], 0)
+    np.testing.assert_equal(water_mask[:, :10], 0)
+    np.testing.assert_equal(water_mask[:, 10:20], 1)
     np.testing.assert_equal(water_mask[:, 20:], 255)