Above 18m: Diving in the Menai Strait

Menai Suspension Bridge
Menai Suspension Bridge

A depth of 18m or less makes a site suitable for all levels of diver – and first up in this series is the Menai Strait, which separates Anglesey from mainland North Wales. Photography by MARK EVANS and MARTIN SAMPSON

The Menai Strait is a narrow band of water that splits the Isle of Anglesey from the Welsh mainland. Harsh currents rip through here at a serious rate of knots, and it is the last place you’d want to find yourself going for an impromptu drift-dive!

However, on the Anglesey side of the Strait right under the spectacular Menai Suspension Bridge – one of two bridges that span the water – you can find a couple of shore dives which, done at precisely the right time so that you catch the short slack period, will turn up carpets of anemones, crabs galore and myriad varieties of fish.

Arrival at the site

 Arrival at Site
Arriving at the dive-site

To get to the entry-point, you need to drive into Menai on the Isle of Anglesey and then follow the signs for the bridge. This will take you down ever-smaller roads, culminating in a single-carriageway road with passing places that passes directly under the high arched supports of the suspension bridge. 

There are a couple of parking spaces right under the arch going overhead, but the rest of the road has double yellow lines – and the traffic wardens can be extremely predatory. If you don’t get lucky and snap up one of the two parking spaces, the best bet is to pull over to the right-hand side of the road and unload all your kit, get into your drysuit and then move your car to the nearest suitable parking spot.

Dive briefing

There are two separate dives here. The first means entering the water to the right-hand side of the suspension bridge and is a scenic bimble around the rocky supports and one of the main arches. According to Martin Sampson, owner of SSI dive centre Anglesey Divers, based in Holyhead, it is a great dive, but there were already several buddy-pairs heading out on that route, so we opted for dive two.

The second dive enters the water on the other side of the suspension bridge. You’ll find a wooden gate leading from the road onto a square grassed area, and you can stash your kit safely there, just through the gate on the left-hand side, while you go to park your vehicle.

“The first thing I noticed was the incredible amount of dahlia anemones on the seabed. In places it was literally a carpet of these colourful animals”

A beautiful capture of Dahlia
Dahlia anemone

Getting to the water’s edge involves a bit of a daring climb down some extremely narrow stone steps. It’s hard enough with a single cylinder on your back, but with a twin-set you have to adopt the “mountain-climber” approach – this is certainly a place where sidemount divers will be in their element!

Once at the water’s edge, wade out until you’re waist-deep and don your fins, then swim out on your back until you’re in a couple of metres and can descend. As you drop down, look for some thick black cables lying on the seabed and running out into the middle of the Strait. 

These telecommunications cables, which actually go right across the Strait, make navigation a doddle – you just follow one out, and then follow it back to shore again, looking at the marine life around you as you do so. You will usually end up at a depth of 13-14m after 25-30 minutes, which is a good time to turn and make your return, because the period of slack water is not long here.

The dive

There were four of us, so Martin split us into two buddy teams and we each set off on a different cable. These days finding the cables in the shallows can be quite interesting, because they are massively overgrown with seaweed, kelp and algae, but persist and sooner or later you’ll come across one – they are as thick as a drainpipe, so once you have one in your sights, it’s fairly easy to keep track of it.

My buddy Nigel Abbott is an Anglesey local, so I pressed him into a spot of modelling during the dive. We found a cable within a few seconds, luckily, and then set off on the dive.

The depth stays fairly constant at 3-4m for a while, then drops off into 5-7m before you find yourself on a gentle slope. Once you get out of the shallows, the thick kelp and seaweed growth drops off, and it is easier to maintain visual contact with the cable over a sand and rock bottom.

The vis in the shallows was only a couple of metres, but it increased to 4-5m once we were deeper, albeit with plenty of detritus floating around.

The beauty of branching sponge
Anemones abound

The first thing I noticed were the incredible numbers of dahlia anemones on the seabed. In places these colourful animals seemed to form a carpet. The only other place where I have seen so many and in such different colour varieties is off the west coast of Ireland.

Edible crab straits
Edible crab
Hermit Crab
Hermit crab

The other main critters on display were crabs – lots of crabs. And every species you can imagine, from common to edible to lively velvet swimming crabs. They were everywhere! We found one large dead edible crab lying on its back, making a fine meal for a small mountain of common shore crabs.

Spider crab
Spider crab
At the water edge
Dead crab provides a feast for other marine life

Apart from the odd goby and a single juvenile pollack, we didn’t really see that many fish, until on the way back towards shore we encountered a small dogfish, which let me get one shot of it before it vanished into the gloom.

18m – Basking Shark
Small dogfish

When we entered the water, the current was still running slightly, meaning we were finning against it gently to maintain position while making our way down the cable, and then on the way back up, the tide had turned and we were finning the opposite way as we headed to shore. The current absolutely screams through the Straits, so you have to ensure that you time your dive to perfection.


TYPE OF DIVE: Relatively easy entry from the shore
DEPTH 16-18m possible but 12-14m more common
MARINE LIFE: Various crabs, dogfish, dahlia anemones
VISIBILITY: Varies, the team had 3m in the deeper sections
SEABED: Sand, silt, pebbles
HAZARDS: Current, boat traffic
LOOK OUT FOR: Crabs of all shapes, sizes and species, from common and shore to edible and velvet swimming; dogfish; masses of different coloured dahlia anemones.

ANGLESEY DIVERS: This SSI and PADI dive-centre has been in business since 1991. It is owned and operated by Martin Sampson, who has a wealth of experience (he is navigator on the Holyhead all-weather lifeboat) on the local area. The centre is situated in Holyhead at the end of the A55 dual carriageway, so is easily accessible, and this positioning enables it to reach all the main dive-sites quickly and simply. It offers training from beginner to professional. The shop is compact but well-stocked, and can offer air and nitrox fills to 300bar from its Bauer compressor.

VIVIAN DIVE CENTRE: Duttons Divers runs this PADI dive-centre near Llanberis in the heart of Snowdonia National Park, which offers an array of courses as well as gas fills. Alongside the picturesque on-site quarry, which is ideal for training or just for a nice freshwater dive (it is also where the Scuba Diver test team conducts most of its reviews), it also offers a variety of shore- and boat-diving excursions to the North Wales coastline and Anglesey, including a special tour that hunts for migrating basking sharks.



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Dee Cee
Dee Cee
6 months ago

Locals would have your guts for garters. It’s the Menai Strait, apparently. Not ‘Straits’.

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