Index: trunk/tests/test_acceptance.py
===================================================================
diff -u -r199 -r200
--- trunk/tests/test_acceptance.py	(.../test_acceptance.py)	(revision 199)
+++ trunk/tests/test_acceptance.py	(.../test_acceptance.py)	(revision 200)
@@ -252,6 +252,38 @@
         assert extracted_data.data_dict["lat"] == coordsBOX["LAT"]
         assert extracted_data.data_dict["lon"] == coordsBOX["LON"]
 
+    def test_extract_data_with_sea_mask(self):
+        expected_sea_mask = np.ones((10, 10))
+        expected_sea_mask[7][4:] = 0
+        expected_sea_mask[6][7:] = 0
+        expected_sea_mask[8][3:] = 0
+        expected_sea_mask[9][3:] = 0
+
+        steplon = 0.5
+        lonl = 3
+        lonr = 7.5
+        steplat = 0.5
+        latl = 52.5
+        latu = 57
+        coordsBOX = {
+            "LON": np.arange(lonl, lonr + steplon, steplon).tolist(),
+            "LAT": np.arange(latl, latu + steplat, steplat).tolist(),
+        }
+        timeWAMy = list(range(1981, 1987))
+        Input_DataBOX = InputData(
+            input_coordinates=coordsBOX,
+            input_variables=["swh"],
+            input_scenarios=["era5"],
+            input_years=timeWAMy,
+            is_gridded=True,
+        )
+
+        dir_test_data = TestUtils.get_local_test_data_dir("chunked_data")
+        extracted_data = ExtractData.get_era_5(dir_test_data, Input_DataBOX)
+        assert extracted_data.data_dict["lat"] == coordsBOX["LAT"]
+        assert extracted_data.data_dict["lon"] == coordsBOX["LON"]
+        assert np.array_equal(expected_sea_mask, Input_DataBOX.sea_mask)
+
     def test_extract_gridded_data_multivariable(self):
         chunked_lon, chunked_lat = ChunkDataUtils.get_default_chunked_lon_lat()
         coordsBOX = {"LON": chunked_lon, "LAT": chunked_lat}