Blue Cavern in Two Harbors offers a complex underwater environment featuring a mix of reef, wall, wreck, and cave topography. The site ranges from 10 to 40 metres in depth, with an average of 18 metres. Divers experience visibility between 20 and 30 metres, though conditions are challenging due to strong currents and potential entanglement risks within the cave sections. Access is by boat only. Given the water temperatures of 13 to 16 degrees Celsius, a drysuit or thick wetsuit is recommended. Divers must remain vigilant regarding heavy boat traffic and maintain strict buoyancy control throughout the dive.

Bird Rock, located 800 metres from the shore of Two Harbors, offers a diverse underwater environment featuring a reef, wall, and kelp forest. Divers can explore depths ranging from 5 to 30 metres, with an average depth of 18 metres. The site is accessible only by boat and is suited for intermediate divers. Marine life frequently encountered includes California sea lions, Garibaldi, and Kelp bass. Less common sightings include Leopard sharks, California moray, Eagle rays, Horn sharks, California spiny lobster, and various nudibranchs. Visibility typically ranges from 10 to 30 metres. Divers should be aware of potential hazards including boat traffic, surge, and strong currents.

Ship Rock near Two Harbors is a complex site featuring a reef, pinnacle, and wreck set within a kelp forest. Divers encounter depths ranging from 5 to 50 metres, with an average of 25 metres. Conditions are variable, with visibility between 3 and 30 metres and strong currents that require careful planning. Water temperatures remain cool, between 14 and 17 degrees Celsius, making thermal protection essential. Due to the depth, current, and potential for low visibility, this site is suited for intermediate divers. Boat access is required, and divers must remain vigilant for boat traffic at the surface. Night diving is permitted for those experienced with these conditions.

Sea Fan Grottos is a boat-access site located off Two Harbors, featuring a combination of caverns, reef structures, and kelp forests. Divers can explore depths ranging from 8 to 12 metres, with an average depth of 8 metres. Visibility at the site typically spans 9 to 23 metres. The area experiences moderate currents, and divers should remain cautious of surge and swell, particularly near the shallower reef sections. As the site includes cavern areas, it presents an overhead environment that requires careful navigation and buoyancy control. This site is suitable for beginners, though an open water certification is the minimum requirement for entry.

Crane Point, located off the coast of Two Harbors, offers a diverse underwater environment featuring natural reef, kelp forest, and artificial reef structures. Divers typically explore depths between 10 and 15 metres, with an average depth of 12 metres. The site is suitable for beginners, though divers should remain mindful of potential surge and swell conditions during boat entry and exit. Visibility ranges from 10 to 30 metres, providing clear views of the layered kelp forest. Due to the presence of kelp, divers should keep their equipment streamlined to avoid entanglement. The site is accessible year-round and supports night diving, with mild currents generally prevailing.

Fishermans Cove in Two Harbors offers a varied underwater environment featuring reef and kelp forest topography. Located 50 metres from shore, the site is accessible by both boat and shore entry, making it suitable for beginners. Divers can expect depths ranging from 6 to 21 metres, with an average depth of 12 metres. Visibility typically spans 9 to 24 metres. Water temperatures range from 15C to 18C, with potential thermoclines occurring between 18 and 24 metres. Divers should remain aware of boat traffic, potential entanglement in kelp, and surf conditions. Facilities including parking, toilets, showers, and equipment rental are available nearby.

Fraggle Rock is a diverse marine site near Two Harbors, Santa Catalina Island, featuring a combination of reef, kelp forest, and pinnacle topography. This site is accessible only by boat and is suitable for beginners, with depths ranging from 10 to 65 metres. Conditions are generally mild, though divers should be aware of potential surf. Visibility is excellent, typically spanning 25 to 80 metres. Species recorded around this area include California sea lions, Garibaldi, California moray, horn sharks, Spanish shawl nudibranchs, and California spiny lobsters. Water temperatures fluctuate between 12C and 17C throughout the year.

Harbor Reefs, located off the coast of Two Harbors, features a combination of reef structures and kelp forest terrain. Divers typically explore at depths between 15 and 20 metres, with an average depth of 17 metres. The site is accessible by boat only, situated 750 metres from shore. Conditions include mild currents and visibility ranging from 10 to 30 metres, though thermoclines and upwellings can cause rapid changes in water temperature and clarity. Divers should be aware of boat traffic, surge, and the presence of sea urchins and sharp rocks. A thick wetsuit is recommended due to water temperatures between 15 and 19 degrees Celsius.