In 1944 it was serving as a hell ship when a United States Navy submarine torpedoed it, sinking it with the loss of between 3,000 and 5,000 lives.

[6] She had a single screw, driven by a three-cylinder triple-expansion engine built by John Dickinson and Sons of Sunderland.

[9] In 1935 the Far Eastern Steamship Co Ltd A/S acquired Havø, renamed her Mabuhay II, and appointed Johan Gran to manage her.

On 5 November that year the Imperial Japanese Army requisitioned Ryūsei Maru[12] for its Railways and Shipping Section.

On 24 February 1944 Ryūsei Maru left Surabaya, Java for Ambon, Maluku carrying about 6,600 men: 1,244 Japanese Army soldiers, 2,865 Indian prisoners of war, and 2,559 rōmusha conscripted labourers.

[12] Allied naval intelligence was aware of the convoy, and the US Navy sent the submarines Rasher and Raton to the Bali Sea to intercept it.

At 2045 hrs on 25 February, Rasher sank Tango Maru by torpedo at position 7°25′S 115°06′E / 07.41°S 115.10°E / -07.41; 115.10, about 25 nautical miles (46 km) north of Bali.