Don Isidro was a fast, modern motor ship built in 1939 by Friedrich Krupp Germaniawerft in Kiel for the De La Rama Steamship Company's inter-island passenger and cargo service in the Philippines. She measured 97.8 m (320.9 ft) and 3,261 GRT and was driven by two nine-cylinder turbocharged diesels at up to 20 knots. After Japan attacked the Philippines in December 1941, she was chartered by the US Army as a transport and blockade runner.

She sailed from Brisbane on 27 January 1942 bound for Corregidor with rations and ammunition. On 19 February 1942 – the day of the first raids on Darwin – Japanese fighters strafed her about 25 miles north of Bathurst Island, destroying her lifeboats, and dive bombers then set her on fire. Captain Rafael Cisneros tried to beach her on the Tiwi coast, but she grounded about three miles offshore when her engines failed. Eleven of her 67 crew and one of the 16 soldiers aboard were killed; the detachment commander, Second Lieutenant Joseph Kane, later died of gangrene in Darwin. The Florence D was sunk nearby the same day.

The wreck lies off the north-west Tiwi coast at about 11°42.3'S 130°02'E. Its remains are protected under Commonwealth historic shipwreck legislation, and two relics – reportedly a silver salt dish and platter – are held by the Museum and Art Gallery of the Northern Territory.

For divers, Don Isidro is more a historical landmark than an accessible dive: remote, undocumented and on a coast with strict Tiwi access rules. It matters as part of the story of the 19 February 1942 raids and the Filipino seamen who died in them. Anyone contemplating a visit should contact the NT Heritage Branch and Tiwi Land Council first.

The wreck site lies off the north-western Tiwi Islands at about 11°42'S 130°02'E, a long, exposed boat trip of several hours from Darwin across Beagle Gulf and along the west coast of Bathurst Island. The west coast of Bathurst Island from Deception Point to Cape Fourcroy is a Tiwi exclusion zone for fishing and landing, and a Tiwi Land Council permit is needed to go ashore anywhere. There is no operator; any visit would be a self-organised expedition, and the wreck is a protected historic shipwreck.

Exposed coast facing the Timor Sea. Only feasible in the dry season (May–October) on calm days at neap slack water. Westerly sea breezes and afternoon trade-wind chop make the long return uncomfortable.

Wet-season monsoon winds, cyclones (November–April) and box jellyfish rule it out. Visibility inshore off the Tiwi coast is reduced by run-off from Tiwi rivers after rain and by spring-tide currents, so late dry-season neaps offer the best chance of clear water. Allow a generous weather margin for the crossing of Beagle Gulf in both directions.

No established dive plan – depth and extent of remains are unpublished. Any visit should be treated as a survey dive, with no contact with the wreck.

No operator. Rarely if ever visited by recreational divers; heritage survey and private expedition only.