In the morning, 'Hosei Maru' is in the Sunda Strait when she is discovered by Dutch submarine O-19.

At 12:22, O-19 fires two bow torpedoes at the port side of HOSEI MARU from a distance of only 450 meters, but both torpedoes pass under the target without exploding.

HOSEI MARU's lookouts see the torpedoes pass under the vessel. The ship desperately turns to port to prepare for another torpedo attack, but at 12:25, O-19 surfaces ab aft HOSEI MARU and makes ready for gun action.

HOSEI MARU replies with small arms. O-19's machine guns immediately silence resistance. At a range of only 250 to 300 meters, O-19´s gun crew fires 86 8.8 cm shells into the small coastal tanker before her deck gun jams.

Due to the very short range, almost every shot hits home and sets the vessel afire. White smoke ascends from the hold where the paraffin is stored. Captain Muranaka Ribee orders “Abandon Ship”. As the only lifeboat was crushed and blown into the sea by shellfire, the men jump into the water. About 25 survivors cling to a capsized lifeboat and floating debris. A hail of machine gun fire sends off HOSEI MARU which drifts burning and sinking abaft O-19 that soon departs.

At about 13: 00, HOSEI MARU sinks bow first at 05-05S, 106-07E. About 1430, the survivors are sighted by a seaplane which radioes for assistance. In the evening, auxiliary subchaser KAIRYU MARU arrives and picks up 38 survivors including all 9 crew members, but 10 passengers are missing. At 1825, KAIRYU MARU sends message that among the 38 men picked up, four are seriously wounded and 10 slightly wounded. Of the nine crew members, Captain Muranaka and the 2nd Officer Takashima Nisaburo are seriously wounded. All survivors are landed at Djakarta. [3]

• Marhisdata ID 5243.
• combinedfleet.com.