Sitiaogou is a deep reef and canyon system located off Lanyu, Taiwan, characterised by complex topography and strong currents. This site is strictly for advanced divers, with depths ranging from 25 to 42 metres and an average depth of 30 metres. Divers experience high visibility between 30 and 50 metres in water temperatures of 25 to 29C. Due to the strong currents and overhead environments within the canyons, boat access is required for all entries. The site is suitable for drift diving and night diving, though navigation is demanding. Divers should plan entries around slack tide to manage the flow through the canyon structures.

Badaiwen Aquarium is a reef site located 3000 metres off Lanyu, Taiwan. The reef structure sits at depths between 15 and 20 metres, with an average depth of 17 metres. Divers experience visibility ranging from 20 to 50 metres and mild currents, though conditions can vary. Access is by boat only, and the site is suitable for intermediate divers. Night diving is permitted. Due to potential surf and strong currents, divers should monitor depth gauges and local conditions closely. Facilities available include equipment rental, air fills, and guided tours.

Yixian Tian is a dramatic canyon and pinnacle site located off Lanyu. The topography features a narrow channel cutting through the reef, creating a signature slot formation. Divers typically explore depths between 15 and 40 metres, with an average depth of 25 metres. Visibility ranges from 20 to 30 metres, providing clear sightlines along the canyon walls. The site is subject to moderate currents that can shift quickly, requiring intermediate skill levels. Access is by boat only, and divers should remain aware of surge and swell during entry and exit procedures. Species recorded around this area include sea kraits, clown triggerfish, regal angelfish, and various nudibranchs.

Green Field is a boat-access dive site off Lanyu, Taiwan, characterised by shallow reef terrain. The site features a wall that extends to 70 metres, requiring divers to monitor their depth gauge closely. Conditions are variable, with strong currents that can shift quickly and push divers off the reef. Marine life recorded at the site includes wrasses, groupers, Pacific Orange-spine Unicornfish, rock cod, Powder-blue Surgeonfish, Striped Surgeonfish, Bird Wrasse, Moorish Idol, Indo-Pacific Sergeant Major, hawkfish, Lined Bristletooth, and snails. Due to the potential for strong currents and the depth of the wall, this site is suitable for intermediate divers who possess strong buoyancy control.

Sankuaishih is a marine dive site off the coast of Lanyu, Taiwan, featuring a shallow reef top that transitions into a wall and drop-off. The topography descends from 5 metres to depths exceeding 30 metres, with an average depth of 20 metres. Divers encounter moderate currents that require solid buoyancy control. Visibility is variable, ranging from 20 to 50 metres. Access is by boat only, and the site is suitable for intermediate divers. Night diving is available through local operators. Due to the potential for strong currents and boat traffic, divers should maintain awareness of their surroundings and plan their dives to work into the current.

Badaiwan is a deep-water site off Lanyu featuring a combination of wreck and canyon topography. The site lies at depths between 38 and 41 metres, with the wreck structure itself located between 17 and 22 metres. Visibility is high, ranging from 30 to 50 metres, allowing for clear views of the canyon walls and wreck during descent. Due to the depth, overhead environments, and potential for moderate currents, this site is suitable only for advanced divers. Boat access is required. Divers should monitor their depth closely and avoid entering enclosed internal areas of the wreck. Guided tours are recommended to navigate the canyon layout effectively.

The Badaiwan Wreck is an artificial reef located off Lanyu, Taiwan, resting at depths between 20 and 38 metres. This site is suited for advanced divers due to the overhead environment, potential for strong currents, and deep profile. Visibility ranges from 20 to 50 metres, allowing for clear views of the structure. Access is by boat only. Divers must manage buoyancy carefully to avoid entanglement risks within the wreck. A dive torch is essential for penetration and night diving. Water temperatures remain between 25 and 29 degrees Celsius throughout the year, typically requiring a 3 mm wetsuit.

Uren Harbor is a sheltered bay on Lanyu, Taiwan, featuring a combination of shallow reef structures and seagrass beds. Divers can explore this site at depths ranging from 10 to 15 metres. The location offers visibility between 20 and 50 metres, providing clear views of the underwater topography. Water temperatures remain between 25 and 30 degrees Celsius throughout the year. Entry is via the shore, and divers should be prepared for moderate currents. Due to the presence of sharp coral and potential for entanglement with bottom growth, careful buoyancy control is required. The site is suitable for beginners, with typical dive times lasting approximately 45 minutes.