The Singapore was a 964-ton steamer wrecked in January 1877 at what is now called Singapore Rock, off Keswick Island in the South Cumberland group north-east of Mackay. The Marine Life Network records that the wreck structure is 'still relatively large' and is covered in coral growth, making it one of the more substantial historic wrecks accessible in the Mackay region. After nearly 150 years, the timber has gone and the iron remains have been absorbed into the reef, so divers see coral-encrusted plates, frames and machinery rather than a recognisable ship.

Fish use the structure as shelter: turtles, barracuda and rays are listed, together with the reef fish typical of the Cumberland Islands – coral trout, sweetlips, damsels, wrasse and parrotfish. The site is within a Marine Park green zone, so it is protected from fishing. Conditions are the main consideration.

Mackay's huge tidal range drives strong currents around the islands, and visibility is best at slack water on neap tides. Keswick is reached by the island ferry or private boat from Mackay, and there is no dive shop on the island, so divers must bring all gear and fills. Precise coordinates and depths for the wreck are not published in the sources reviewed, and historic wreck protection should be assumed – look but do not touch or remove anything.

Divers combining it with Keswick's shore dives should plan the wreck for the neap-tide slack and leave the sheltered bays for the tidal periods in between.

Keswick and St Bees islands lie in the South Cumberland group roughly 30–35 km north-east of Mackay. A passenger ferry/barge service runs to Keswick Island from Mackay (about 1 hour), landing near Connie Bay; there are also light-aircraft flights. Private boats launch at Mackay Harbour or Mackay Marina (Mackay Harbour boat ramp, Slade Point) and cross in about 45–70 minutes depending on conditions, passing Slade Point and Flat-top Island.

Egremont Passage separates Keswick from St Bees and runs strong tides. There is no dive shop on the islands – bring all gear and fills from Mackay. The wreck lies at Singapore Rock off Keswick Island; reach it by boat from Keswick or directly from Mackay.

Mackay has the largest tidal range on the Great Barrier Reef coast (springs exceed 6 m), so tidal streams around the Cumberland Islands and in passages such as Egremont Passage are strong and visibility is closely tied to the tide – dive neap tides at slack water. The south-east trades (15–25 knots April–September) make crossings rough; the calmest windows are the build-up months (September–December) and winter lulls. Visibility is typically 5–12 m inshore, often worse after wind or wet-season rain (January–April) from the Pioneer River and local creeks.

Marine stinger season (box jellyfish and Irukandji) runs roughly November to May – wear a full-length stinger suit or wetsuit with hood and gloves, carry vinegar. Cyclone season November–April; tropical lows and cyclones can close sites and damage coral (TC Yasi 2011, TC Debbie 2017). Cyclone Hamish (2009) and Cyclone Debbie (2017) affected reefs in the region.

At slack water, descend beside Singapore Rock and search the reef around it for the coral-covered hull remains, circling at 5–10 m. Keep the rock on one side for navigation.

No regular dive-charter operator currently runs scheduled trips in the Mackay region; divers use private boats, club trips (local dive clubs) and occasional charter boats from Mackay Marina. Nearest dive shops and fills in Mackay.