diff --git a/scripts/base_network.py b/scripts/base_network.py
index b23fa0c1..f2eab220 100644
--- a/scripts/base_network.py
+++ b/scripts/base_network.py
@@ -411,10 +411,13 @@ def _replace_b2b_converter_at_country_border_by_link(n):
 
 def _set_links_underwater_fraction(n):
     if n.links.empty: return
-
-    offshore_shape = gpd.read_file(snakemake.input.offshore_shapes).unary_union
-    links = gpd.GeoSeries(n.links.geometry.dropna().map(shapely.wkt.loads))
-    n.links['underwater_fraction'] = links.intersection(offshore_shape).length / links.length
+    
+    if not hasattr(n.links, 'geometry'):
+        n.links['underwater_fraction'] = 0.
+    else:
+        offshore_shape = gpd.read_file(snakemake.input.offshore_shapes).unary_union
+        links = gpd.GeoSeries(n.links.geometry.dropna().map(shapely.wkt.loads))
+        n.links['underwater_fraction'] = links.intersection(offshore_shape).length / links.length
 
 def _adjust_capacities_of_under_construction_branches(n):
     lines_mode = snakemake.config['lines'].get('under_construction', 'undef')