Sea Caves, anyone?


New member
A bit off-topic, as this is outside the normal mode of cave exploration, but is anyone out there interested in exploring sea caves? Whilst typically nowhere near as long as limstone caves, sea caves are a pretty unique environment. I love exploring them, and the best way, in my opinion is by coasteering.

Yes, you can explore some of them by kayak, especially on very calm days. However, there are many that are too narrow, swelly, or simply impossible to access by kayak. I wrote the following blog post a few years ago about the best sea caves in west Cornwall, where I live:

But, we've subsequently found many more. In fact the north coast of Cornwall is home to loads of real mosters, and it's not uncommon to find sea caves greater than 100m in length. It's a very odd environment to explore indeed, swimming along in the darkness, with the waves rolling in making very haunting noises, and always the possible fear that you might abruplty find yourself in a seal's living room!

Oh, and there is maybe a uniquely Cornish phenomenon - that is sea caves that transition into old mine workings? There are numerous exmaples of this, and it's testament to just how bonkers the Cornish miners or old were. The miners would have accessed either through a shaft inland, or in some cases a very dodgy ledge leading from the cliff to an adit at the back of the sea cave. Many of these means of access are no more, which means the only way to visit these places now is coasteering into them. This video epxloring St. Agnes shows a famous example, but a few others that might be quite unknown, being inaccessible by usual mine exploration methods.

As I said, it's a bit outside the usual remit of caving, and dareisay, sea cave exploration is even more obscure than caving in general? But is anyone else out there doing it at all?


I grew up in St Agnes, now live in Perranporth by Cligga where the mine is. Exploring the sea caves as a kid is what set me on the path of caving! That article about the west coast looks so awesome, I need to get down there more often.

Winnat's Caver

Active member
I loved exploring sea caves in Pembrokeshire when I was young. If you are ever near St Davids, Whitesands beach has fantastic sea caves if you go to the far left and right of the cove.


Well-known member
Huge numbers of sea caves can be found in caving publications and the online registries.


Well-known member
The sea cave at Trevaunance Cove, St Agnes is a fine cave as mentioned. Just extended one 800 miles from there at Balnakeil Bay in Durness. This is probably the finest sea cave I have been in - you can boat up the passage and it has many formations in it.


Well-known member
There's the Green Holes of Doolin, Ireland, some of which you can snorkel at low tide, others are diveable
Nice film. Wouldn't like to use a backmount in there though! I am wondering if that is Mermaid's Hole on the film as it is a large passage compared with the ones I visited in the 80's.