25 April 1932: During patrol of Philippine Sea S-32 detected large convoy. After successful attack she sunk 3 ships for total 9000 tons then escaped unhurt (T2).
27 June 1932: Patroling Philippine Sea, S-1 attacked and sunk 3000 tons and 5000 tons merchant ships, for total 8000 tons (T10).
14 September 1932: Near Carolines, Bass on patrol sunk massive 16000 tons fleet oil tanker Notoro (T20).
17 September 1932: Nautilus repeated Bass success tree days later, sinking another 16000 tons oiler Erimo (T21).
19 September 1932: Narwhal sunk first enemy warship, light cruiser Jintsu, paying the biggest price (T21).
