Hanauma Bay is a reef site located within an ancient volcano crater on Oahu. The site is suitable for beginners, offering shore access with an average depth of 2 to 4 metres and a maximum of 5 metres. Visibility typically ranges from 12 to 24 metres. Divers and snorkellers should be aware of potential hazards, including rip currents, strong currents, and sharp coral. Facilities at the site include parking, toilets, showers, rinse stations, equipment rental, a cafe, and first aid. Guided tours and air fills are available. The site is open for both day and night diving, with typical sessions lasting 120 minutes.

Electric Beach is a shore-entry reef dive located in Oahu. The site features shallow reef topography, providing a forgiving environment for practising buoyancy and observation skills. Water temperatures remain between 24 and 27 degrees Celsius throughout the year. Divers and snorkellers frequently encounter Pacific Orange-spine Unicornfish, Redlip Parrotfish, wrasses, and Hawaiian Convict Surgeonfish. Other species recorded here include the Pacific Sailfin Tang, Fourspot Butterflyfish, Lagoon Triggerfish, Bird Wrasse, Palenose Parrotfish, and Bluefin Trevally. Rarer sightings include the Day Octopus, Achilles Tang, Yellow-edged Moray, and Turkey Moray. Visibility and currents vary considerably, so check local conditions before entering the water. Facilities are not guaranteed, so arrive prepared with all necessary equipment.

Halona Blow Hole on Oahu offers a shallow reef and cave dive ranging from 3 to 7 metres. This site features an overhead cave environment that requires intermediate skill levels to navigate safely. Divers experience visibility between 9 and 12 metres with water temperatures ranging from 24 to 27C. Access is via a shore entry that requires caution due to surf, shore break, and sharp coral. Strong currents are common throughout the area, necessitating constant attention during the dive. Parking is available on site, though the area can become crowded on weekends. Typical dive duration is approximately 40 minutes.

Koko Craters is a marine site located 500 metres off the coast of Oahu, featuring a combination of natural reef and artificial reef structures. The site is suitable for beginners, with an average depth of 10 metres and a total depth range between 9 and 12 metres. Access is by boat only. Conditions vary, with visibility ranging from 12 to 45 metres and currents typically described as mild. Divers should be aware of potential hazards including boat traffic, sharp coral, and the possibility of strong currents. A typical dive at this location lasts approximately 45 minutes.

Spitting Cave on Oahu offers a dynamic marine environment combining a wall, drift, and cave system. Divers experience depths ranging from 6 to 17 metres with an average of 11 metres. The site is defined by strong currents and an overhead cave environment, requiring solid buoyancy control and situational awareness. Visibility is consistently 30 metres, and water temperatures range between 24 and 26 degrees Celsius. Access is strictly by boat. Due to the presence of strong currents, rip currents, and surf, this site is suited for intermediate divers. Divers should exercise caution regarding the overhead environment and remain aware of potential hazards including sea urchins and sharks.

Koko Kai Park in Oahu is a shore-entry reef site suitable for intermediate divers and snorkellers. The site features an average depth of 5 metres. Conditions at this location are variable, with strong currents and surf present, requiring careful planning. Facilities available at the park include parking, toilets, and showers. Due to the nature of the environment, divers and snorkellers should be aware of sea urchins in the area. The water temperature ranges between 24C and 27C throughout the year.

Angler's Reef in Oahu is a diverse site featuring a combination of natural reef, wall, and artificial structures. Located 805 metres from shore, this site is accessible only by boat. Divers can expect depths ranging from 6 to 14 metres, with an average depth of 10 metres. The site is suitable for beginners, though conditions vary and strong currents are frequently encountered. Night diving is permitted at this location. Species recorded around this area include various moray eels, wrasses, groupers, parrotfish, triggerfish, and reef sharks. Divers should be aware of the presence of sharks and strong currents when planning their visit.

Baby Barge is an artificial reef site featuring an upright barge resting on the seabed. The wreck sits at depths between 21 and 26 metres, with an average depth of 23 metres. A notable topographical feature is a 5 to 6 metre ledge located on the left side of the barge, which drops to a depth of 26 metres. Divers should be aware of the overhead environment presented by the wreck structure. Access to this site is by boat only, located approximately 8 kilometres from shore. Conditions include moderate currents and visibility ranging from 10 to 30 metres. This site is suitable for intermediate divers.