Wreck Tour 30 : The Kos XVI

The Kos XVI
The Kos XVI

It's a long way out and on the deep side, but how often do you get the chance to savour an intact minesweeper? asks JOHN LIDDIARD. Illustration by MAX ELLIS

The Kos XVI is a very rare kind of wreck, a minesweeper that is intact and upright, and was not blown to bits by a mine!

It started life as one of a fleet of Norwegian whaling boats named Kos I to Kos XXIII. During World War Two the Kos XVI was converted to a minesweeper and served with the Royal Navy.

Most minesweeper wrecks I have dived were blown up after striking a mine, but not the Kos XVI, which was sunk in a collision in August 1941. So far as I know there was no loss of life, so it is not a military war grave.

The wreck is located at a depth of 38m on the outside edge of the Rough gasfield, about 38 miles south-east of Flamborough Head. Again, it is a bit further offshore than the usual Wreck Tours, but it is such an interesting wreck I had to include it.

Our tour begins roughly amidships on the port side (1). The whole wreck lists slightly to port, making this side at 36m a metre or so deeper than the starboard side. The superstructure is an open steel framework covered in a thick growth of plumose anemones. Considering that the ship has been down almost 60 years, the wooden decking is in most places surprisingly intact, though it has rotted almost completely away in some areas.

Working towards the stern, you can choose between swimming inside or outside a covered part of the deck (2). Along the side of the deck, sets of heavy cables run the length of the ship.

Bearing in mind its wartime role, these would include copper de-gaussing cables and steel hawsers used to tow minesweeping gear, in addition to the cables used to steer the ship.

Peering inside the superstructure, an oversized boiler and engine are visible, but more of that later. Just where the superstructure ends, the stern has split almost completely from the rest of the ship (3).

This damage was begun by the collision that sank the Kos XVI, and completed by time, tides and gravity.

Above the stern a large steering-quadrant is still attached to the rudder-post (4). Below the stern, the rudder has bent to one side and is now buried, but the large iron propeller is still attached to the shaft and, like most of the ship, is covered in anemones (5).

Beneath the stern is a slight scour, maximum depth 38m. Here I found one of the biggest lobsters I have ever seen. I don't eat seafood, but everyone else on the boat also left it alone, because it was so nice to see a lobster that huge and (more likely) it would have been a bit tough to eat anyway.

Rounding the stern to the starboard side, the split here is much larger and stove in at the edges (6), indicating the point of collision. I can imagine the helmsman of the other vessel turning hard to port at the last minute in an effort to clear the stern of the Kos XVI, and not quite making it.

The split has made access to the aft cabins and engine-room a simple matter. Swimming forward inside the wreck takes you past a pair of toilets, the engine and the back of the boiler, with an easy exit on the starboard side to the main deck (7).

If you prefer to remain outside, crossing the roof of the engine-room will take you past the ventilation hatches (8) and a collapsed pair of boat-derricks. Engineering drawings of the Kos XVI show a twin Hotchkiss gun-mount fitted just aft of the ventilation-hatches, but I could find no trace of this.

As befits a fast whaling ship, the boiler and engine are massively oversized. Most large freighters are listed as having “triple expansion engines” but the steam engine in the Kos XVI has five cylinders of steadily increasing size, indicating quintuple expansion to obtain the maximum power available from the steam. It was no doubt this availability of power and speed that led to the Kos XVI’s conversion to a “minesweeping corvette” for wartime service.

Having exited the engine-room and passing the rest of the boiler-room outside the ship, a collapsed area (9) indicates the remains of the wooden wheelhouse. Originally standing higher than the rest of the superstructure, this has now collapsed into the fuel bunkers below.

The next cabin forward (10) is another minesweeping addition, the remains of the generator room. The structure has partly collapsed, but looking inside it is possible to make out the tops of two diesel generators used to provide electrical power for the minesweeping equipment.

The foremost cabin above deck (11) is the crew’s toilets and washroom. It has been substantially reinforced to support a 2-pounder gun-mount on its roof.

On the bow deck to the port side lies a spare anchor (12) and a large metal conical structure (13). This is the noise-maker for sweeping acoustic mines. Over the side of the hull here you can see one of the pivots at the end of an A-frame that lowered beneath the bows for minesweeping (14).

Ascending the bows, both anchors are still in place (15), with chain leading back to the anchor-winch (16). Beneath this, another spare anchor rests on the starboard side of the deck. To the starboard side of the crew’s washroom, the 2-pounder gun, fallen from the mount above, lies flat against the deck (17).

Having toured the wreck, all that remains is to return to amidships (18) and ascend the line to decompress.

My dives on the Kos XVI were made using nitrox with a Draeger rebreather, giving me about 30 minutes’ bottom time from 40-minute overall dive-times.

Using air, a 20 to 25-minute bottom time on a computer would give about the same overall dive-times and, if you’re not busy sketching and taking photos, 20 minutes should be enough to allow you a gentle tour of the entire wreck.


Altogether there were 23 ships called Kos. All were built in the 1930s in Britain for the Norwegian whaling company Hvalfangersisk Kosmos, writes Kendall McDonald.

The Norwegians had their Kos fleet of whalers built in Middlesbrough yards. The Kos XVI, completed in 1932, was one of the smaller ships at 258 tons, compared with her younger sisters, which weighed in at 353 tons. It was 36m long, with a beam of 7m and a draught of 4m.

It was used for whaling until the outbreak of WW2, and escaped to Britain with many others of the Kos clan when the Germans invaded Norway. Like the others, it was requisitioned by the Royal Navy and used as an armed minesweeper. Two sister ships – Kos XXIII and Kos XXII – were sunk during the battle for Crete in May 1941.

The Kos XVI was lost later that year when it was in collision in the North Sea on 24 August, but there were no reports of casualties.

GETTING THERE: From the south, follow the A1(M) north, then take the A64 past York to Scarborough. From the north leave the A1(M) on the A61 or A168 for Thirsk, then take the A170 to Scarborough.

DIVING AND AIR: John Liddiard dived the Kos XVI from the liveaboard Jane R, boarding at Scarborough.

ACCOMMODATION: For accommodation details ashore check tourist information at Scarborough, Bridlington or Hornsea.

LAUNCHING: Slips are available at Flamborough, Bridlington and Hornsea. However, the Kos XVI lies 38 miles from Flamborough Head and 30 miles from Hornsea, so the use of a hardboat is strongly recommended.

TIDES: Slack water is three hours after high or low water Scarborough.

HOW TO FIND IT: The co-ordinates are 53 52.00N, 00 36.001E (degrees, minutes and decimals), approximately 38 miles south-east of Flamborough Head, on the outside edge of the Rough gasfield.

QUALIFICATIONS: With the wreck standing only a few metres up from a maximum depth of 38m, this dive is suitable only for experienced sport divers and above, ideally using nitrox for decompression.

FURTHER INFORMATION: Admiralty Chart 121, Flamborough Head To Withernsea. Ordnance Survey Map 101, Scarborough, Bridlington & Filey. Ordnance Survey Map 107, Kingston Upon Hull. Dive Yorkshire, by Arthur Godfrey & Peter Lassey. Catchers And Corvettes 1860 To 1990 by John Hartland.

PROS: A rare opportunity to dive a minesweeper with all its specialist equipment in place.

CONS: A long way offshore.

Thanks to Gordon Wadsworth, Helen Jarratt, Andy Moll and members of Severnside BSAC.

Appeared in Diver, August 2001


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Al Forbes
Al Forbes
6 months ago

Excellent and fascinating

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