Sea Kayaking at the Blue Lagoon, Pembrokeshire
The Blue Lagoon in Pembrokeshire is one of the most photographed and talked-about spots on the North Pembrokeshire coast.
Located near Abereiddy, this former slate quarry is now a striking tidal lagoon surrounded by sheer cliffs. While it’s popular with coasteerers and adventurous teenagers, the most peaceful way to experience it is by sea kayak — particularly around high tide.
Yes, we’ve even launched off the wall in kayaks.
A Former Slate Quarry
The Blue Lagoon was an active slate quarry until the early 20th century.
The cliffs were blasted to allow access for shipping, and eventually the sea claimed the site. Today, the vertical rock faces drop dramatically into deep, still water.
The lagoon is rumoured to be around 80 metres deep. While exact depth varies with tide and sediment, it is significantly deeper than it appears from above. Only a handful of experienced freedivers have ever reached the bottom.
Because the lagoon is semi-enclosed, the water is often calm. When conditions are right, it reflects the emerald-green tones that Pembrokeshire is known for.
Why Visit the Blue Lagoon by Sea Kayak?
Approaching the Blue Lagoon by sea kayak changes the experience completely.
From land, you look down into it. From a kayak, you move quietly across its surface and notice the texture of the rock, the changes in water colour and the echoes against the quarry walls.
At high tide, access is straightforward from the open coast. At lower water, exposed rocks and swell can make entry more technical.
If you are already exploring nearby features such as the Witches Cauldron, combining both locations makes for a memorable stretch of coastline.
👉 Sea kayaking in the Witches Cauldron
Fossils and Falling Slate
Behind the small beach, slate fragments regularly fall during warm summer months. The rock heats at different rates, which can cause sections to loosen and drop.
Within the slate, fossilised remains can still be found. The most well-known are graptolites — small colonial marine animals that lived around 500 million years ago.
It’s a reminder that this dramatic location is far older than the quarry that shaped it.
Tryn-y-Castell Tower
The round tower above the lagoon on Tryn-y-Castell is often mistaken for a defensive structure.
In reality, it is believed to be a 19th-century navigation beacon, unrelated to the quarry itself. From the water, it forms a striking silhouette against the skyline.
Is the Blue Lagoon Suitable for Beginners?
The lagoon itself is usually calm. However, access depends on tide, swell and wind direction. Aberieddy itself is a known surf beach.
On settled days around high tide, it can be suitable for newcomers. On more exposed days, conditions on the approach may require more experience.
Understanding when to enter and when to avoid a location like this is part of responsible sea kayaking.
If you’re interested in exploring this coastline properly:
👉 Sea kayaking in Pembrokeshire
Or if you’d like to develop the skills to move confidently around tidal features:
