Index: trunk/tests/test_extract_data.py
===================================================================
diff -u -r137 -r138
--- trunk/tests/test_extract_data.py	(.../test_extract_data.py)	(revision 137)
+++ trunk/tests/test_extract_data.py	(.../test_extract_data.py)	(revision 138)
@@ -15,27 +15,50 @@
 
 
 class Test_get_era5:
-    @pytest.mark.systemtest
-    def test_given_list_of_coordinates_then_subset_is_extracted(self):
-        # 1. Given
-        # When using local data you can just replace the comment in these lines
-        dir_test_data = Path(TestUtils.get_local_test_data_dir("chunked_data"))
-
-        input_data = InputData()
+    @pytest.fixture
+    def default_lon_lat(self) -> Tuple[np.array, np.array]:
         lonmin = -5
         lonmax = 11
         dlon = 0.5
         latmin = 50
         latmax = 62
         dlat = 0.5
-        lon = np.arange(latmin, latmax + dlat, dlat)
-        lat = np.arange(lonmin, lonmax + dlon, dlon)
+        lon = np.arange(latmin, latmax + dlat, dlat)[4:8]
+        lat = np.arange(lonmin, lonmax + dlon, dlon)[4:8]
+        return lon, lat
 
+    @pytest.mark.integrationtest
+    def test_verify_seamask_has_sea_positions(
+        self, default_lon_lat: Tuple[np.array, np.array]
+    ):
+        # 1. Given
+        # dir_test_data = Path(TestUtils.get_local_test_data_dir("chunked_data"))
+        dir_test_data = Path("P:\\metocean-data\\open\\ERA5\\data\\Global")
+        mask_filepath = dir_test_data / "ERA5_landsea_mask.nc"
+
+        # 2. Verify netcdf
+        assert mask_filepath.is_file()
+        result_possea, LON, LAT = ExtractData.get_seamask_positions(mask_filepath)
+
+        # 3. Verify mask
+        assert result_possea.size > 0, "No sea positions found in mask."
+        assert LON.size > 0, "No masked lon coordinates."
+        assert LAT.size > 0, "No masked lat coordinates."
+
+    @pytest.mark.systemtest
+    def test_given_list_of_coordinates_then_subset_is_extracted(
+        self, default_lon_lat: Tuple[np.array, np.array]
+    ):
+        # 1. Given
+        # When using local data you can just replace the comment in these lines
+        dir_test_data = Path(TestUtils.get_local_test_data_dir("chunked_data"))
+
+        input_data = InputData()
         input_data.input_variables = ["swh"]
         input_data.input_years = [1981, 1982]
         input_data.input_coordinates = {
-            input_data.longitude_key: lon,
-            input_data.latitude_key: lat,
+            input_data.longitude_key: default_lon_lat[0],
+            input_data.latitude_key: default_lon_lat[1],
         }
 
         # 2. When
@@ -74,7 +97,7 @@
         dlat = 0.5
         lon = np.arange(latmin, latmax + dlat, dlat)
         lat = np.arange(lonmin, lonmax + dlon, dlon)
-        input_data.input_coordinates = {"LAT": lat[1:2], "LON": lon[1:2]}
+        input_data.input_coordinates = {"LAT": [lat[1:2]], "LON": lon[1:2]}
         input_data.input_years = [1981, 1982]
 
         # 2. When