Ohinau offers diverse underwater topography ranging from shallow reefs to deep wall drop-offs. The site is characterised by broken rock and boulder terrain, featuring large cracks, crevices, and several swim-throughs. The south-western side is defined by abundant seaweed, while the north-eastern face consists primarily of bare rock with occasional weed edges. Depths range from 5 to 30 metres. This site requires boat access and is suitable for intermediate divers due to strong currents and deep sections. Typical dives last 45 minutes, with water temperatures fluctuating between 15C and 21C throughout the year.

Crayfish Bay at Cathedral Cove features rocky ledges and extensive kelp forests. This marine site offers depths ranging from 2 to 13 metres, with an average of 8 metres. Snorkellers can observe a variety of marine life, including snails, which are very common, alongside uncommon sightings of Common Sydney Octopus, Red Comb Star, abalone, Pink Snapper, and crabs. Rarer species such as the Knobbed Triton, tube worms, and bluebottles are also recorded. The site is accessed from the shore and is suitable for intermediate snorkellers. Divers and snorkellers should be aware of moderate currents, potential surf, and boat traffic in the area.

Matapaua Bay, located near Cathedral Cove, offers a sheltered reef environment suitable for beginner divers and snorkellers. The site features shallow reefs extending from the shore, with depths ranging from 5 to 15 metres. Conditions are generally mild, though divers should remain aware of potential boat traffic and surf. Species recorded around this area include wrasses, blue maomao, pink snapper, and southern rock lobster. Other marine life occasionally observed in the vicinity includes long-nosed fur seals, common Sydney octopus, and various ray species. Facilities at the site include parking and toilets, providing convenient access for shore-based activities.

Danger Rocks at Cathedral Cove is a complex marine site featuring a reef that drops to 30 metres, alongside pinnacles, canyons, and walls. The topography includes large valleys with sandy bottoms, deep cracks along the walls, and numerous swim-throughs. Flat-topped rocks are covered in kelp and seaweed. The site reaches depths between 8 and 56 metres, with an average of 10 metres. Access is by boat only, and conditions involve variable currents and potential surge. Divers should be aware of sea urchins. This site is suited for intermediate divers.

Whale Rock at Cathedral Cove is an exposed dive site featuring sloping walls, cracks, and crevices. The eastern side consists of covered ridges descending to 45 metres, while the western side features a steep wall dropping to between 20 and 25 metres. Due to strong currents and potential surf, this site is suitable for advanced divers only. Divers should avoid the area during prevailing winds exceeding 15 knots or swells over 1 metre. Species recorded around this area include wrasses, blue maomao, pink snapper, and southern rock lobster. Navigation is straightforward using natural features.

Green Island, located off Cathedral Cove, is a diverse marine site featuring a combination of reef, cave, wall, and pinnacle topography. Divers can explore drop-offs ranging from 10 to 25 metres, with an average depth of 18 metres. Access is strictly by boat, as the site lies 8 kilometres from the shore. Conditions vary, with moderate currents and visibility typically between 10 and 30 metres. Hazards include surge, strong currents, and potential entanglement. Species recorded around this area include wrasses, green moray, long-nosed fur seal, eagle ray, common Sydney octopus, scorpionfish, snake eel, pink snapper, tube worm, crab, goatfish, sea hare, and sea star.

Otama Beach, located near Cathedral Cove, features a white-sand shoreline with rocky outcrops and tide pools at its western end. This site offers shallow reef systems that are accessible from the shore, making it suitable for beginners. Conditions are generally calm, though snorkellers should be aware of potential surf and the presence of sharks in the area. Water temperatures fluctuate between 15C and 22C throughout the year. Toilets are available for visitor use at the beach. This site provides a straightforward snorkelling experience for those looking to explore coastal reef formations in the Coromandel region.

Stanley Island, located near Cathedral Cove, offers a shallow marine dive experience with a depth of approximately 7 metres. The site is subject to variable conditions, and divers should be aware of the presence of strong currents in the area. Water temperatures fluctuate throughout the year, ranging from 15C in the winter months to 22C during the peak of summer. Due to the nature of the currents, this site is best suited for divers who are comfortable managing changing water movement. Access to the site is typically by boat from the surrounding Coromandel region.