FOR OUR FIRST-EVER NORTH WALES WRECK TOUR, I have picked a splendid little wreck that just about anyone can enjoy. The mussel-dredger Segontium met her fate on the way to the scrapyard in 1984.
When I dived the Segontium last year, skipper Scott Waterman had dropped a shot across the stern and it ran right past the side of the funnel (1), so that is where our tour will begin.
Having been down for only 20 years or so, the Segontium is amazingly intact. The funnel stands upright from the superstructure, with a pair of ventilators right behind it.
I enjoyed quite good visibility but, should you be less fortunate, this provides an easy clue as to which way is forward and which side is which.
Dropping to deck level at 26m on the port side, the railing (2) is intact and draped with several layers of trawl net. Staying clear of the netting and heading aft, at the stern the otherwise clear deck is broken by a forest of ventilators (3) of different shapes and sizes. On a smaller scale they could easily be used as a desk-tidy. Everything is smothered in anemones, even the deck.
The side of the wreck is now clear of nets, making it safe to drop over the side and deeper to have a look at the stern. The seabed is a dark silty sand, slightly scoured to 31m below the square rudder (4).
Between the rudder and the hull, the propeller is shrouded in a heavy steel guard with more trawl net pulled tight under it (5). Its ironic that a guard designed to keep nets and ropes clear of the propeller when the Segontium was working has now trapped another fishing vessels nets.
Ascending the starboard side of the stern, there are no nets and it is safe to venture a little further forward to meet the deck near a small pair of mooring bollards (6).
Having got the deep part of the dive out of the way, now is the time for a leisurely inspection of the super-structure. Behind the funnel and ventilator stacks, the engine-room ventilation hatches are open (7), though on a ship of this size they are far too small to swim through. Nevertheless, shining a strong light inside may reveal a glimpse of the engine.
By the starboard railing a grating above the deck marks the point at which a lifeboat would have been stored (8).
The railing here has a gap that looks intentional rather than damage subsequent to sinking.
Forward of the funnel, an open doorway (9) marks a shaft and ladder down to the engine room. Again, its very tight for a diver, and all but the most suicidal of hole-fiends will again have to be content with shining a torch down to see what bits of machinery they can glimpse.
The aft part of the wheelhouse is steel, but the forward section must have been wooden, because it has rotted completely away, making it easy to swim around what would have been the inside (10). To either side of the wheelhouse, steps lead down to the main deck at 28m. Bearing in mind that all the nets are on the port side, I would recommend that you stick to starboard.
On the main deck, the hold covers have partly caved in to give a shallow valley along the centre of the deck. Almost immediately a pair of square hold hatches (11) provide a view into the hold and a way in for those so inclined.
Next on the starboard side comes a small hoist (12). There is no corresponding hoist on the port side; like most fishing vessels the Segontium would have been set up to work over only one side.
Further forward, a square frame stands from the deck (13), followed by a small winch and another hatchway down to the hold below (14), again showing the one-sided working of the ship.
The mast (15) has a pair of beams angled against it, originally used to lay the mussel-dredging equipment over the side, though this gear was removed from the Segontium before it left on its final journey.
Steps lead up to the bow deck, the port side again obstructed by nets and the starboard side clear. It is a small bow deck with barely enough room for the anchor winch (16).
Depending on how happy you are about putting a dip at the end of an otherwise quite restrained dive profile, on the starboard bow close to the seabed there is a dinner-plate-sized hole partly obscured by enormous plumose anemones (17).
Rounding the bow, on the port side and slightly higher, there is a considerable dent (18). Could the Segontium have hit something on its final voyage Or could this have been old damage, or perhaps caused by one of the many trawlers that seem to have lost their nets on this wreck
This is a fairly small wreck, so there is plenty of time to see it all at a relaxed pace, with little if any decompression penalty.
From the bow, a nice ascent route is to follow the mast upwards, popping a delayed SMB from the top at 18m (19).

Thanks to Scott Waterman


She was a dodgy boat. Her stability was suspect. But then, she was designed by engineers, so what can you expect Captain Raymond Phillips, who had been one of the Segontiums captains, was talking to me about the ship, writes Kendall McDonald.
He sounded not the slightest bit upset, and indeed was exceptionally cheerful, when I told him that amateur divers often visit his former command as it lies upright on the bottom of Caernarvon Bay.
I have rarely had so much trouble in tracing a wrecks history as I did with the Segontium. This trouble was largely caused by someone ill-informed putting on a website: Segondium (sic) did not sink in Caernarvon Bay, after a spell in the Caernarvon Maritime Museum, she was scrapped.
This statement hid her true story for some time. Even though the Caernarvon Maritime Museum curator said it was rubbish and that the museum had never had the vessel, the tale sent me careering around in Welsh trawling circles.
Guildhall Museum in London as usual turned out to be the shipwreck-researchers best friend, and dug out details of the Segontium from its vast Lloyds marine collection.
The vessel was built for the Navy at Faversham in Kent and launched into the Swale in 1943. She was designed for use as armament stores tender C165 and spent her war supplying shells and other ammunition to big warships and convoy escorts.
At the end of the war C165 was converted. She appears on the Mercantile Navy list of 1976 as a 192 ton British steel motor vessel with fishing-trawler classification and her port of registry London. She was later owned by Welsh Seafoods of Bangor, Caernarvonshire.
This information sent me back to Wales, and it wasnt long before I found Captain Phillips. He told me that well before he took command she was named Segontium after an ancient Roman fort in Caernarvon. Later she was again converted, this time into a mussel-dredger. It wasnt a very popular kind of fishing, as she was equipped to hoover up the mussels by using a water dredge, said the Captain.
How did the 65ft dredger finally sink Captain Phillips was not aboard for her last voyage in 1984, which was with a scratch crew taking her to be scrapped. She foundered in rough weather, he said. Water just came in and that was that. All aboard were saved.

A hole close to the keel in the starboard side of the bow - is this what sank the Segontium

and doorway and shaft down to the engine-room

anchor winch

steps to the bow deck and porthole in the rear wall of the wheelhouse


GETTING THERE: Follow the A55 across North Wales to Anglesey. Once over the bridge, take the slip road and turn right to Menai Bridge (the town, not the bridge itself). Turn towards the waterfront by the newsagent and post office opposite the HSBC. The boat picks up from the pontoon in front of the harbour office.
TIDES: Slack water occurs 90 minutes before high water and low water Liverpool. On a neap tide, slack can last as long as two hours.
HOW TO FIND IT: Scott Waterman advises that the position given in his book is a mistake. The actual GPS position is 53 05.936N, 004 33.231W.
DIVING AND AIR: Scott Waterman, Quest Diving Charters, 01248 716923 or 07974 249005.
ACCOMODATION: Quest can put you in contact with the whole range of local accommodation, ranging from B&B in the pub by the harbour office to camping outside town..
QUALIFICATIONS: Suitable for any sport diver, at a depth well suited to making the most of nitrox.
FURTHER INFORMATION: Admiralty Chart 1970, Caernarvon Bay. Ordnance Survey Map 114, Anglesey. Anglesey Wrecks and Reefs, Andy Shears and Scott Waterman. Anglesey tourist information 01407 762622, www.anglesey.gov.uk

PROS: Ideal for the average club dive, where everyone can have a decent time on the wreck and see it all without getting into too much decompression.
CONS: Stay clear of the port side, which is heavily draped with nets.