Split Bommie is at the very southern end of Hastings Reef. Passions of Paradise describes it as multiple split bommies, with a swim-through at 12 m, and notes that it is used only in light winds because swell wraps around the end of the reef. That exposure is also what makes it interesting: at the southern tip a current line often forms, bringing in small reef sharks and pelagic fish that patrol the edge of the flow.

The bommies themselves are split by cracks and clefts, some wide enough to swim through, and the main swim-through at 12 m is the centrepiece of the dive. The coral is robust and healthy, shaped by moderate water movement, with plate and boulder corals and soft corals in the shelter of the clefts. Fish include the usual reef species on the bommies, parrotfish, wrasse, fusiliers, damsels and coral trout, and schools of trevally or mackerel in the current line.

Turtles are common on Hastings. Because of the current and occasional surge, this is a better dive for divers with some experience; newly certified divers can do it with a guide in calm conditions. Divers Den also describes a Split Bommie at Norman Reef, which is a different site.

On a calm day it is one of the more exciting moorings on Hastings. Visibility at the tip of the reef is often better than inside, commonly 15-25 m, because of the clean water carried in by the current. The site is a good contrast to the sheltered bommies at Stepping Stones, and the two are often dived on the same day, Split Bommie first while divers are fresh and the conditions are at their calmest.

Boat access only. Cairns day boats leave from the Reef Fleet Terminal (1 Spence Street) and the neighbouring Marlin Marina on the city waterfront, with check-in between about 7:00 and 8:00 am; most operators run transfers from city and northern-beaches accommodation, and there is paid parking near the terminal. The run of about 50 km out through Trinity Inlet and across the lagoon to Hastings Reef takes around 75 minutes on a fast catamaran and noticeably longer on slower dive boats or into a south-easterly chop.

Split Bommie is a Passions of Paradise mooring used only in light winds; Cairns Dive Adventures also lists it for Hastings. Enter from the stern steps.

The prevailing south-east trade winds (typically 15-25 knots from April to September) are what limit Cairns outer-reef diving: above about 25 knots trips may be cancelled, and exposed eastern moorings are used only in light winds. Summer northerlies are gentler but make north-facing moorings choppy. Box jellyfish and Irukandji are present from about November to May (stinger suits on every dive), and the cyclone season runs November to April, when a system in the Coral Sea can close the reef for days.

Visibility drops after heavy rain and strong winds; spring is usually calmest and clearest. Hastings has moorings on all sides, so there is almost always a sheltered option. Split Bommie is at the exposed southern tip of the reef where swell wraps around, so it is only used in light winds; a current line often runs off the end of the reef.

Descend to the bommies, locate the swim-through at 12 m and pass through with the guide, then explore the other split bommies. Keep an eye on the current line off the reef end, where pelagics gather, but stay in its lee. Safety stop on a bommie top.

Passions of Paradise – day trips in light winds only; other operators occasionally; Hastings is also worked by Reef Experience, Divers Den, Tusa Reef Tours, Aqua Quest, Down Under Cruise & Dive and the Reef Encounter liveaboard; the mooring used on any day is chosen by the skipper according to wind, tide and other boats