Llanddwyn Island is a tidal island featuring rocky inlets and secluded coves. This shore-entry site is suited for intermediate snorkellers who can navigate moderate currents and surf. Water temperatures range from 9C to 16C, reflecting the cold conditions typical of the region. Divers and snorkellers should be aware of potential hazards including rip currents, strong currents, and low visibility. The site provides access to parking, toilets, showers, and a cafe. A typical visit lasts approximately 60 minutes. As a tidal location, the topography is best explored during high tide when the rocky inlets are fully submerged.

Segontuim is a wreck dive located in Pembrokeshire, United Kingdom, resting at depths between 20 and 31 metres with an average depth of 27 metres. This site is suited for intermediate divers due to the moderate currents and entanglement hazards present on the structure. Visibility is typically limited to 5 metres, requiring careful navigation and the use of torches. Water temperatures range from 9C to 16C, necessitating appropriate thermal protection. Access is by boat only, situated 14 kilometres from the shore. The wreck provides a habitat for various temperate marine life, including reef fish and invertebrates common to the region. Guided tours and air fills are available locally.

Rhoscolyn at Borth Wen is a coastal site featuring a mix of reef and seagrass habitats. Divers and snorkellers can access the water directly from the beach or the boat slip. The topography includes a rocky shoreline with gullies extending toward a small island. Depths at this site range from 1 to 8 metres, with an average depth of 4 metres. Conditions are generally mild, though water temperatures fluctuate between 9C and 16C throughout the year. The site is suitable for beginners, though users should remain aware of boat traffic and the cold water. Facilities available at the location include parking, toilets, and showers.

Porth Castell is a reef site in Pembrokeshire, United Kingdom, offering shore access for both divers and snorkellers. The topography features dramatic rock formations, a small island, and deep gullies. Depths range from 1 to 12 metres, with an average of 5 metres. Divers and snorkellers may encounter snails, which are very common, alongside uncommon species including wrasses, compass jellyfish, barrel jellyfish, tube worms, common moon jellyfish, sea squirts, shannies, clingfish, European green crabs, and rockpool prawns. Conditions vary, with visibility between 3 and 20 metres and mild currents. Hazards include boat traffic, rip currents, strong currents, and surf. Facilities available include parking, toilets, showers, a cafe, and a dive shop.

Trearddurr Bay in Pembrokeshire offers a shore-entry dive site featuring a mix of reef and wreck topography. Divers can explore rocky structures and nooks at depths ranging from 5 to 15 metres, with an average depth of 10 metres. Conditions vary, with visibility typically between 5 and 15 metres and moderate currents. The site is suitable for intermediate divers, with typical dives lasting around 45 minutes. Night diving is permitted. Hazards include boat traffic, potential entanglement, strong currents, and surf. Facilities available at the site include parking, toilets, a cafe, and a dive shop.

Craig-y-Mor in Pembrokeshire offers a rugged marine environment defined by underwater gorges and kelp-covered walls. Snorkellers should plan their visit around high tide to safely navigate the inner gullies. Water temperatures fluctuate between 9C and 16C throughout the year. Marine life recorded at the site includes common snails, alongside less frequent sightings of wrasses, brittle stars, sea stars, tube worms, and various crab species such as rock crabs and European green crabs. Jellyfish, including compass, barrel, and common moon varieties, are occasionally present. Due to the nature of the terrain and tidal requirements, this site is best suited for intermediate snorkellers.

Trefor Pier is an artificial reef site located in Pembrokeshire, United Kingdom. Divers can explore the structure at depths ranging from 2 to 8 metres, with an average depth of 6 metres. This shore entry site is suitable for beginners and offers mild currents. Visibility typically ranges between 5 and 10 metres. The site is accessible for night diving, with a typical dive duration of 60 minutes. Facilities available at the location include parking, toilets, air fills, and a cafe. Divers should remain aware of potential hazards, including boat traffic, entanglement risks, and surf conditions. Water temperatures fluctuate between 8C and 17C throughout the year.

Porth Dafarch in Pembrokeshire is a Blue Flag beach on Holy Island providing a shallow shore entry suitable for beginners. The site features a mix of rocky reef, kelp forests, and artificial structures. Divers and snorkellers can explore depths ranging from 2 to 8 metres, with an average depth of 6 metres. Visibility varies between 5 and 20 metres, and currents are generally moderate. Facilities at the site include parking, toilets, and showers. Due to its accessible nature and consistent conditions, it is a popular location for training. Divers should remain aware of potential boat traffic in the area.