Penguin Cove in Milford Sound is a marine dive site featuring a reef, wall, and drop-off topography, complemented by a kelp forest. The site reaches a depth of 12 metres and requires boat access. Divers should be prepared for mild currents, cold water temperatures ranging from 13C to 17C, and variable visibility. Due to the potential for cold water, depth, and currents, this site is suited for intermediate divers. Species recorded around this area include long-nosed fur seals, broadnose sevengill sharks, wrasses, scorpionfish, crabs, black coral, butterfly perch, snails, triplefins, and rock-pool shrimp.

Penguin Cove in Milford Sound is a reef and wall dive site accessible only by boat. Divers can expect a consistent depth of 11 metres. Conditions at this site vary, with visibility typically ranging between 5 and 15 metres and currents remaining mild. Due to the water temperatures, which fluctuate between 13 and 17 degrees Celsius throughout the year, appropriate thermal protection is required. The site is suitable for beginner divers. Hazards include cold water and low visibility, so divers should plan their dives accordingly.

Harrison Cove is a sheltered site in Milford Sound featuring a unique environment where a freshwater tannin layer allows deep-water black coral to grow at shallow depths. The topography includes reefs, walls, and kelp forests, alongside the structure of the floating Underwater Observatory. Divers and snorkellers experience depths ranging from 10 to 18 metres, with an average of 10 metres. Visibility varies between 4 and 15 metres. The water column consists of a cold freshwater surface layer over saltwater ranging from 13 to 17 degrees Celsius. Access is by boat only, and the site is suitable for beginners.

Cray's Crack is a marine dive site located within Milford Sound, New Zealand. The site features a depth of approximately 10 to 11 metres. Water temperatures in this area fluctuate between 13C and 17C throughout the year, with the warmest conditions occurring in February and March. Divers should be prepared for variable conditions typical of the Fiordland region. Access to this site is generally by boat. As a marine environment, the site is defined by its physical topography and underwater features within the fiord system.

Deepwater Basin in Milford Sound offers a sheltered shore entry located near the boat ramp. The site features a combination of reef and wall topography, suitable for beginner divers. Depths range from 8 to 18 metres, with an average depth of 12 metres. Divers should expect mild currents and variable visibility between 3 and 15 metres. Water temperatures are consistently cold, ranging from 13 to 17 degrees Celsius, necessitating the use of drysuits or thick wetsuits. Typical dive times are approximately 45 minutes. Hazards include boat traffic, cold water, and low visibility. Parking is available at the site.

Clio Rocks is a vertical wall and reef site located in Milford Sound. The site is characterised by walls encrusted with a high density of suspension feeders that thrive in the nutrient-rich, shaded waters. Access is by boat only. Divers and snorkellers should be prepared for strong currents and cold water conditions. The site features a permanent freshwater layer on the surface, which can range from 5 centimetres to over 10 metres deep, overlying a warmer saltwater layer. Due to the depth, low visibility, and potential for overhead environments, this site is best suited for intermediate divers.