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Dive at Porth Dafarch, west coast of Anglesey in North Wales


Dive Briefing at Porth Bafarch

Mark Evans is a long-time fan of Anglesey, and one of his favourite dives off this North Wales island is the sheltered little bay of Porth Dafarch, which is shallow, easy to navigate and boasts a plethora of marine life

Dive at Porth Dafarch

Photographs by Mark Evans

Anglesey is a small island sitting off the northwest tip of Wales, and for divers, the great benefit is that if one side is blown out by the – often unpredictable – weather, you can often find somewhere on the opposite side to get wet. There are a vast range of dive sites in the coastal waters, ranging from scenic rocky reefs to shipwrecks from all eras, and many can be accessed from the shore or via a short RIB ride, but for this issue, I am going to focus on Porth Dafarch, a sheltered bay that lies on another, even-smaller island that perches off one side of Anglesey, Holy Island.

Arrival at Porth Dafarch

Arriving at Porth Dafarch, west coast of Anglesey in North Wales

Porth Dafarch lies on Lon Isallt, which leads from Trearddur Bay – which boasts several great shore dives itself and is the launching point for RIB jaunts to various wrecks and reefs – to Holyhead. It is effectively the last bay you will come to before the main road carries on towards South Stack, or a right turn heads into Holyhead itself.

This sheltered bay is extremely popular with families, so depending on the time of year and time of day, it can be very busy – best bet is to get there early to secure a decent spot for your car. Parking is along the side of the road, or down the slope next to the toilet block that leads to the beach steps (and in the summer season, a handy snack wagon doing burgers, bacon sarnies, coffees, teas and other essentials, and an ice-cream van for sweet treats).

You can then kit up at your leisure next to your vehicle, and it is just a short walk down the steps on to the sandy beach and the sea.

Dive briefing at Porth Dafarch

Dive Briefing at Porth Bafarch

There are various options when it comes to diving Porth Dafarch, but all of them are better on a high tide, when if you are lucky you might attain a depth of 7-8m. Diving on a high tide also makes it easier to get in and out of the water, as you can walk in and out via the nice smooth, sandy beach, and not have to clamber over slippery, seaweed-covered rocks and boulders.

The central portion of the bay comprises of vast swathes of sand, with the odd crop of rock topped by seaweed and kelp. You can mooch about here looking for cuttlefish, rays and flatfish, but if there is any sort of water movement – and that includes wayward fins – the sand can get kicked up and seriously reduce visibility.

The best bet is to enter the water on one side of the bay or the other and explore along the edge of where the rocky cliffs meet the sandy seabed. This is what makes navigation so easy – you just set off with the rocks on your right shoulder (or left, depending on which side of the bay you are diving) and take a nice, slow meander out to sea. In places the kelp growth can make it difficult to see where the rock face is, and there are a few gullies on both sides of the bay which can lure unwary divers into a dead end, but it is no hardship to retrace your steps and continue with the dive once you have regained your bearings. And if all else fails, you are so shallow, you can make a slow ascent next to the rock wall and do a quick surface recce before descending to finish your dive. When you have had enough – a single cylinder will last for ages, regardless of your SAC rate, given the shallow depth – all you have to do is turn around and put the rock wall on the other shoulder for your return journey.

There can be the odd speedboat, RIB or jet ski entering the bay, so if you want to play really safe – especially if exploring the middle portion – then it is worth towing an SMB, but to be honest, as long as you stay close to the rocks at the sides of the bay, then you will be fine. However, as always, ascend slowly and listen for any boat traffic.

“And if all else fails, you are so shallow, you can make a slow ascent next to the rock wall and do a quick surface recce before descending to finish your dive”

The different dive routes

Porth Dafarch, west coast of Anglesey in North Wales

Both sides of Porth Dafarch have their merits, but I prefer the right-hand route, which has more-vertical walls and more-pronounced gullies and overhangs. It is worth going slow, so you can peer into all the nooks and crannies, which is where the shrimps, prawns and crabs all hang out – a small torch is a useful addition to aid in the critter spotting.

In the areas where the kelp grows quite thick, pollock and various species of wrasse will patrol above and in the fronds, and check out the sand below this prolific cover, as I have often encountered resting dogfish.

If the vis is good enough, peel off from the wall and explore into the central section of the bay a little way, as this is a good place to find flatfish and cuttlefish camouflaged on the seabed. Just remember to return to the rocks for continue or finish your dive.

The left-hand side is still a great dive, but the rocky walls are not as clearly defined, and there are a series of shallow gullies you can thread in and out of, or hop from one to the other. Expect the same species of marine life in this area.

“This sheltered bay is extremely popular with families, so depending on the time of year and time of day, it can be very busy – best bet is to get there early to secure a decent spot for your car”

Dive centres

Porth Dafarch

Close by in Holyhead you can find Anglesey Divers (, run by Martin Sampson, who offers SSI and PADI courses and can supply air fills, equipment and kit rental. Porth Dafarch is one of his regular training spots, so if you have any additional queries about diving here, Martin is the person to ask.

A little further afield, on mainland Wales, there is Duttons Divers ( at Vivian Quarry. PADI Course Director Clare Dutton offers air fills, training to pro levels, and leads guided shore and boat diving around the North Wales coast, while Vivian itself – a picturesque inland dive site in its own right – is a good place for a dip enroute home to rinse your kit off in freshwater.

What to expect at Porth Dafarch, Anglesey

Type of dive

Shore dive, best experienced at high tide.

The Depth

Expect to get around 7-8m maximum at high tide, though the majority of the time you will be lucky to break 5-6m.

Marine life and what to look out for

The rocky walls on either side of the bay are home to blennies, gobies, wrasse, pollock, lobster, edible crabs, spider crabs, velvet swimming crabs, hermit crabs, common crabs, cuttlefish, octopus, flatfish, dogfish, starfish, shrimps and prawns.


If the weather has been calm, or blowing from the east, then you can get towards double figures, but expect four to five metres as an average. If the seabed gets disturbed, the vis can be reduced to next to nothing.


Sand, with rocky outcrops in the middle of the bay, and plenty of seaweed and kelp.


Occasional boat traffic, but stick close to the rock walls and you should be well clear of any issues.

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Jon Partington
Jon Partington
4 years ago

Thanks for this article, it is great to see our local sites getting a bit of attention. So often diving publications get so excited about jetting off to warm waters that we forget teh gems on our doorstep. Porth Dafarch is a lovely spot and usually a little quieter that its bustling neighbour Treaddur Bay.
You did not mention Diving Services on Ravenspoint Road, Treaddur Bay who do air and if I was being very picky, some of your photos look like the little bay south of Porth Dafarch (also a nice dive spot, but no burger van).
Our club dives here regularly but we tend to bring our boat so that we can access the SS Missouri which lies in the entrance to Porth Dafarch

ade hillyer
ade hillyer
4 years ago

Sounds brilliant
it would help if there was some contact number so we can speak to the dive centre. if they can help out with some number of rental places or camp sites really close, better still.


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