Manta Channel is a tidal channel at the northern end of North Reef, near the North Reef lighthouse, listed by the Marine Life Network with a depth of about 15 m and a reputation for manta rays. The tidal flow through the channel concentrates plankton, which attracts mantas to feed. Details beyond this are limited, but the setting suggests a classic channel drift: coral-lined edges, a sandy or rubble floor, and fish life drawn by the current.

Mantas are most likely when the tide is running and plankton is concentrated, and the cooler months are generally best for manta activity in the southern Great Barrier Reef. Because it is a tidal channel, the dive needs careful planning: near slack water it is relaxed, but at peak flow it can be strong. A live boat with a skipper watching divers' surface markers is essential.

The site is visited only by private boats and occasional liveaboards, and it pairs well with the shallow SS Cooma wreck on the same reef. It suits divers with Advanced certification and drift experience. As with any manta site, divers should stay low, avoid chasing the animals and let them approach, which gives the best encounters and least disturbance.

The Capricorn Group lies 60-100 km north-east of Gladstone. Private boats launch from Gladstone Marina (Bryan Jordan Drive; ramps, fuel and trailer parking) and cross the shipping approaches and open water, typically 2-4 hours depending on vessel and destination; the Capricorn Bunker liveaboards that occasionally visit depart Gladstone or Yeppoon (Rosslyn Bay) and anchor overnight in the lee of the cays. Camping on the national park cays requires a QPWS permit and a camper transfer or private vessel.

Manta Channel is at the northern tip of North Reef near the lighthouse, about 70 km north-east of Gladstone. It is dived from a live boat as a drift through the channel near slack water.

The Capricorn cays are exposed to the south-east trades (often 15-25 knots April-September), which make the Gladstone crossing rough and restrict diving to the lee (north-western) sides. The calmest windows are typically September-December and March-April. Northerlies in spring and summer reverse the sheltered sides.

Tidal currents run strongly around reef edges and channels on springs. Cyclone season November-April. As a tidal channel, the site is dived near slack water or on a moderate flow; wind against tide makes the channel rough.

Drop in at the up-current end of the channel near slack water, descend to 12-15 m and drift through, watching for mantas feeding or passing. Deploy an SMB and surface for live-boat pick-up at the end.

No daily operator. Occasional liveaboard itineraries (for example the 8-diver MV Adori run by Professional Dive Services, 4 days/3 nights from Yeppoon) and fishing/snorkel charters such as Eastern Voyager visit the Capricorn cays; otherwise private boats and camping groups only.