Puffin Island in Pembrokeshire offers a challenging marine environment featuring a mix of reef, kelp forest, and cave topography. Divers can explore depths ranging from 8 to 35 metres, with an average depth of 20 metres. Access is strictly by boat, as the site is located 800 metres from the shore. Conditions are variable, with strong currents and surge present, alongside visibility ranging from 5 to 15 metres. Due to the strong currents and potential for low visibility, this site is recommended for intermediate divers. Typical dive times are approximately 40 minutes. Divers should remain vigilant for boat traffic in the area.

Menai Straights is a reef and drift site located in Pembrokeshire, United Kingdom. The site features depths ranging from 5 to 18 metres, with an average depth of 13 metres. Divers and snorkellers should be prepared for strong currents and low visibility, which averages around 5 metres. Due to the challenging conditions and significant boat traffic, this site is suitable for intermediate divers. Access is available via both shore and boat entries. Facilities at the location include parking, toilets, and air fills. Typical dives last approximately 30 minutes, and night diving is permitted.

Ynys Moelfre is a reef site located 1000 metres offshore in Pembrokeshire, United Kingdom. The reef reaches depths of 10 to 18 metres, with an average depth of 14 metres. Divers encounter strong currents, making it suitable for intermediate skill levels; planning dives around slack water is essential. Visibility typically ranges from 5 to 10 metres. Marine life recorded at the site includes curled octopus, grey seals, squat lobsters, various crabs, brittle stars, common sea stars, and dead man's fingers. Water temperatures fluctuate between 8C and 16C throughout the year. Boat access is required to reach the site, and local facilities include parking, toilets, showers, and a dive shop.

Angel Bay is a rocky cove located at the base of the Little Orme in Pembrokeshire. This site is suitable for intermediate snorkellers and offers shore access. Water temperatures fluctuate throughout the year, ranging from 8C in February and March to 17C in August. Snorkelling conditions vary, and visitors should note that access to the cove is restricted during the autumn months to protect the local grey seal pupping season. As a rocky coastal environment, the site requires careful entry and exit planning. It is recommended that snorkellers monitor local conditions before visiting this exposed coastal location.

Vivian Quarry is a flooded slate quarry in North Wales offering a contained, current-free dive within an industrial setting. The site features submerged quarry walls and artificial reef structures, with depths ranging from 6 to 19 metres. Visibility typically varies between 5 and 10 metres. Due to the overhead environment created by the quarry walls and potential swim-throughs, buoyancy control is essential. The water remains cold throughout the year, making a dry suit, hood, and gloves recommended. The site is suitable for beginners and supports night diving. On-site facilities include changing rooms, air fills, equipment rental, parking, and toilets, providing a convenient location for training and gear checks.

The SS Dakota is a shipwreck located 1609 metres off the coast of Pembrokeshire, United Kingdom. Resting at depths between 10 and 20 metres, with an average depth of 15 metres, the site is suitable for intermediate divers. Access is by boat only. Divers should expect strong currents and limited visibility, typically around 5 metres, making the use of a torch recommended for viewing structural details. Planning dives around slack water is essential to manage the current. Surface intervals require vigilance due to boat traffic, and caution is advised when moving near any sharp rock formations in the area.

Bull Bay, or Porth Llechog, is a coastal site on the north coast of Anglesey featuring a mix of reef and wreck topography. Divers and snorkellers can explore the remains of the paddle steamer Pansy, which are scattered near the rocks on the left side of the bay. The site is accessed from the shore via a shingle and rock beach. Depths typically range from 6 to 10 metres, with an average of 8 metres. Conditions vary, with visibility ranging between 5 and 20 metres and mild currents. Hazards include boat traffic, strong currents, and surf. Facilities available at the site include parking, toilets, and a cafe.

Porth Wen Brickworks in Pembrokeshire offers a unique dive experience where industrial ruins meet the sea. The site features an old harbour area with underwater structures that function as an artificial reef. Divers should note that conditions vary, with visibility often limited and potential hazards including overhead environments and surf. The site is accessed from the shore and is best suited for intermediate divers due to the nature of the underwater ruins. Water temperatures fluctuate between 9C and 16C throughout the year. Snorkellers may also enjoy the sheltered environment of the harbour area.