Mediterranean geography creates submarine opportunities

The Mediterranean was not one undifferentiated patrol area: a boat's base determined which shipping lanes, islands, and coasts it could reach with enough fuel left to return. Malta lay near the central routes linking Italy, Sicily, and North Africa, while Gibraltar and Alexandria served different approaches. Port Said added access near the Suez Canal, and islands divided the basin into distinct operational spaces. This geography made the theatre target-rich, but also meant that patrol locations were dictated by distance, base access, and the enemy's own routes.