Dalkey Sound is a drift and reef dive site located off Dalkey Island, Ireland. The site features depths ranging from 8 to 20 metres, with an average depth of 15 metres. Access is strictly by boat, and the site is suited for intermediate divers due to the presence of strong currents. Visibility at the site typically varies between 5 and 15 metres. Divers should be aware of potential hazards including entanglement, strong currents, and surf. Water temperatures fluctuate throughout the year, ranging from 9C in the winter months to 16C in August. Typical dive times at this location are approximately 30 minutes.

Muglins Rock is a marine reef and artificial reef site located off Dalkey Island. The site is accessible only by boat and is suited for intermediate divers due to strong currents and potential surf conditions. Divers can expect depths ranging from 7 to 30 metres, with an average depth of 15 metres. Visibility at the site typically fluctuates between 6 and 15 metres. Given the challenging conditions and current, boat support is required for all dives. Water temperatures vary throughout the year, ranging from 9C in the winter months to 16C in August. Divers should be aware of the risk of entanglement while exploring the reef structures.

Sorrento Bay, located off Dalkey Island, offers a shallow dive experience featuring a reef and kelp forest environment. The site maintains an average depth of 5 metres, making it suitable for beginners. Divers access the water via a shore entry. Conditions at this location vary, with visibility typically ranging between 8 and 15 metres and currents generally remaining mild. Due to the nature of the coastal environment, divers should be aware of potential rip currents and surf. The site provides a straightforward underwater topography for those exploring the Dublin coastline.

Guide Me II is a wreck dive site located off Dalkey Island, Ireland. The wreck lies at a depth of 17 to 18 metres and is accessible only by boat. Divers should be prepared for moderate currents and visibility ranging between 3 and 8 metres. Due to the nature of the site, it presents an overhead environment and requires awareness of boat traffic. The site is suitable for beginners, with typical dives lasting around 35 minutes. Guided tours and boat charters are available for those planning to visit this marine location. Night diving is also permitted at this site.

Bullock Harbour in Dun Laoghaire offers a marine site featuring both natural and artificial reef structures. The site maintains an average depth of 7 metres. Access is available via both shore and boat entries, making it suitable for beginners. Divers and snorkellers should be aware of variable conditions, including potential boat traffic, entanglement risks, and periods of low visibility. Water temperatures fluctuate throughout the year, ranging from 9C in the winter months to 16C in August. Parking facilities are available near the harbour for those arriving by land.

The Lady's Stairs in Dun Laoghaire is a shore-entry site featuring a combination of natural reef and artificial reef structures. Suitable for intermediate divers and snorkellers, the site reaches an average depth of 11 metres, with a typical range of 10 to 12 metres. Conditions at this location are variable, with visibility ranging from 3 to 10 metres and the potential for strong currents and surf. Divers should be aware of hazards including entanglement, rip currents, and low visibility. Parking is available for visitors. The site is accessible for night diving, with typical dives lasting approximately 40 minutes. Water temperatures fluctuate between 9C and 16C throughout the year.

Sandycove Beach in Dun Laoghaire offers a shore-entry dive featuring a mix of reef and kelp forest habitats. Divers and snorkellers can explore depths ranging from 1 to 15 metres, with an average depth of 8 metres. The site is suitable for beginners, though conditions include moderate currents, surf, and variable visibility between 3 and 10 metres. Divers should remain aware of boat traffic in the area. The site is accessible for night diving, with typical dives lasting around 30 minutes. Species recorded around this area include seals, various jellyfish, catsharks, crabs, and sea stars, though these are not confirmed sightings at this specific location.

UCD Sub Aqua Club in Dun Laoghaire offers a combined natural and artificial reef experience accessible directly from the shore. Divers navigate depths between 5 and 20 metres, with an average depth of 15 metres. Conditions include mild currents and visibility ranging from 5 to 15 metres. Due to the temperate water temperatures, which fluctuate between 9 and 16 degrees Celsius, a drysuit is recommended. The site is suitable for intermediate divers and supports night diving. Shore entry requires careful timing to manage surf and swell conditions. On-site facilities include parking, changing rooms, showers, and toilets to assist with kit preparation.