Pulau Tengah in Karimunjawa, Indonesia, features a distinct reef system characterised by walls and drop-offs. The site reaches depths between 8 and 30 metres, making it suitable for intermediate divers. Access is exclusively by boat, as the site is located 5000 metres from the shore. Divers and snorkellers can expect moderate currents and visibility ranging from 5 to 12 metres. Water temperatures remain consistent throughout the year, typically between 29 and 30 degrees Celsius. Hazards at this location include boat traffic, sharp coral, and the presence of sharks. On-site facilities include toilets, a cafe, and guided tours.

Taka Gede is a reef site located in Karimunjawa, Indonesia, suitable for beginner divers. The site features coral formations in shallow water, with depths ranging from 5 to 18 metres and an average depth of 10 metres. Divers can expect mild currents and visibility between 10 and 20 metres. Access to the site is by boat only, with typical dives lasting 45 minutes. Water temperatures remain consistent throughout the year, ranging between 29 and 30 degrees Celsius. Facilities available in the area include air fills, equipment rental, guided tours, and boat charters. Divers should remain aware of boat traffic in the vicinity.

The Indonor Wreck is an artificial reef located within Karimunjawa National Park, resting at depths between 10 and 16 metres. This site is accessible by boat and features mild currents, with visibility typically ranging from 10 to 25 metres. Divers can explore the hull and interior sections, though caution is required due to sharp surfaces and potential entanglement hazards from loose lines. A torch is recommended to inspect the interior structure. The water temperature remains consistent, generally between 29 and 30 degrees Celsius. This site is suited for intermediate divers who should maintain controlled movements to avoid contact with the wreck's structure.

Karang Torpedo is a historical site located in Karimunjawa, Indonesia, featuring a collection of WWII-era torpedoes resting on the seabed. These historical remnants are now encrusted in coral, creating a unique artificial reef structure that blends history with the surrounding marine environment. The site is accessible only by boat and is suitable for intermediate divers. With a snorkel rating of 4 out of 5, it also provides an accessible experience for those surface swimming. Water temperatures remain consistent throughout the year, typically ranging between 29C and 30C. Divers and snorkellers should be prepared for boat-based entry and exit procedures.

Secret Garden is a reef site located between the main island of Karimunjawa and Menjangan Besar. This site is suitable for beginners, offering shallow depths ranging from 3 to 9 metres. Access is by boat, which is required to reach the location. Conditions are generally calm with mild currents, though visibility can fluctuate significantly between 5 and 30 metres. Divers and snorkellers should be aware of potential hazards, including boat traffic, entanglement risks, and sharp coral. The site provides a straightforward experience for those looking to explore the reef environment in the Karimunjawa National Park area.

Tanjung Gelam, also known as Ujung Gelam, is a reef site in Karimunjawa, Indonesia, offering a rare shore entry point on the main island. The reef begins just metres from the beach, making it suitable for both diving and snorkelling. Divers and snorkellers can explore depths ranging from 1 to 25 metres, with an average depth of 12 metres. Conditions are generally mild with visibility between 5 and 15 metres. The site is well-suited for beginners, though caution is advised regarding sharp coral. Facilities including toilets and equipment rental are available on-site. The habitat supports a variety of reef fish and invertebrates typical of the region.

Penangkaran Hiu in Karimunjawa is a marine site featuring both reef and artificial reef structures. It is primarily known for its shark conservation pens. The site is suitable for beginners and offers a snorkel rating of 3 out of 5. Water temperatures remain consistent throughout the year, ranging between 29C and 30C. Divers and snorkellers can access the site via both shore and boat entries. Conditions are generally manageable with mild currents. As this is a shark conservation area, visitors should be aware of the presence of sharks in the water.

Spot Maer is a reef site located in Karimunjawa, Indonesia, within the Karimunjawa National Park. Known as a coral garden, the site features a vast sloping reef with high coral density. It is a dedicated snorkel location suitable for beginners, with depths ranging from 3 to 9 metres and an average depth of 6 metres. Access to the site is by boat only. Conditions are generally mild with currents described as mild and visibility typically ranging between 10 and 20 metres. Water temperatures remain consistent throughout the year, fluctuating between 29 and 30 degrees Celsius.