Wreck Tour 29: The Turquoise

The Turquoise Wreck Tour
The Turquoise Wreck Tour

For the first time we venture abroad, though within easy striking distance of the South Coast, says JOHN LIDDIARD – to dive an unusual WW2 coaster sunk by an equally novel gunboat. Illustration by MAX ELLIS

THIS MONTH'S WRECK TOUR REPRESENTS a bit of a diversion from our established policy, as the wreck of the Turquoise lies in French rather than UK waters. Nevertheless, it is a popular target with the liveaboard boats that run trips to the Normandy wrecks and the occasional fast day-boat that ventures this far out from the South Coast.

For many UK divers, it is actually more accessible than one or two of the other wrecks we have featured.

And besides all that, it’s a nice wreck with some interesting engineering, so I make no further excuses about selecting the Turquoise!

The 278-ton coaster was originally built in Antwerp in 1932 and operated under a Belgian flag. At the start of World War Two, the ship was captured by the advancing Germans and passed into German naval service as an armed coaster.

Although off the Normandy coast and in the same area as many of the D-Day wrecks, the Turquoise went down following action against a Free French gunboat in 1942, well before the Normandy landings.

The highest point of the wreck is the amidships area, standing some 6-7m proud of the 40m seabed and making a good target for a shotline.

The wreck lies with its bows to the south-west. To get your orientation, the forward end of the amidships area has collapsed inwards (1) between the remaining upright sides of the hull, whereas the aft end is square between the sides of the hull.

With a wreck as small as the Turquoise, I like to get to one end as soon as possible, then meander back along it. On the starboard side, the route to the bows is slightly shallower, as the wreckage has twisted progressively further to port towards the bows.

As with most ships, the bows and stern are significantly stronger than the sides of the holds, and consequently more intact. The skeleton remains of the forecastle bulkhead soon rise above the wreckage (2). Looking inside the forecastle, there are some scraps of uniform cloth and rifle bullets among the debris.

Although sunk in combat, it is unlikely that there were ever any human remains in the forecastle. The scraps of uniform were most likely unworn and left behind when the ship went down.

With the current debate over war graves, it is interesting to note that the French government has no problem with divers exploring military wrecks in French waters. Perhaps this is testament to the sensible “look but don’t take anything” policy towards amateur divers that is rigidly enforced by the French authorities – a model for which I hope our government settles in the end.

The bows have twisted over to lie on the port side, the main feature being a small anchor-winch in the middle of the bow deck (3).

Huge shoals of pouting and poor cod swarm over the bows in the almost slack current, but none seem to get caught in the trawl-net and boom that are tangled across their very tip (4). There is a shallow scour here, leading to a maximum depth of 44m.

Now turning back towards the stern of the ship, a large tube section lies angled back to the seabed (5). This is most likely the remains of a mast.

Although the Turquoise was operated as an armed coaster, there are no signs of the deck-gun that would no doubt have been fitted above the forecastle, or indeed of any other heavy armament. Perhaps it was all salvaged many years ago.

The floor of the forward hold is covered by a thin layer of debris from the sides of the ship and deck. Further back into the amidships area (6), remains include a porcelain sink and an assortment of leather shoes and boots.

To continue towards the stern, you have either to make a diversion outside the hull or above the amidships area (7) for a slight saw-tooth in your dive profile. Here the deck-ribs have caved in towards the centre of the ship above the engines, though the debris is too dense to allow you to see the engines from here.

Descending again closer to the keel, the stern hold has collapsed to port, with the starboard side falling into the hold and the port side falling out across the seabed (8).

The one thing that is obviously missing from the wreck is any sign of a propshaft or propshaft tunnel. Even when a propshaft has been salvaged, there are normally strengthened patches on the keel where the bearings would have been mounted.

The reason is one of the interesting engineering features of the Turquoise – it had a diesel-electric drive. Peering inside the mostly intact stern (9), it’s possible to see what could be the remains of the electric motor that would have driven the propeller. Outside there are no signs of the propeller, which has obviously been salvaged.

Above the stern deck, the remains of the steering mechanism are still in place above the rudder-shaft (10). Like the bows, the stern lies on its port side, with the bollards at the side of the stern partly buried in the sand and gravel seabed (11). Unlike the bows, there is no scour here, and the depth is a level 40m.

Heading back to amidships, the whole of the port side has collapsed out and lies flat against the seabed (12). The bulkhead at the rear of the engine-room (13) has decayed to an open framework, making it possible to see the engines inside.

These would have been coupled to the electric motor at the stern by heavy copper cable but, being non-ferrous, this was no doubt one of the first things to have been commercially salvaged after the war.

To end the dive, there are many suitable points at which to tie in a delayed SMB above the engines (14), or simply ascend the shotline.

The whole wreck can be seen comfortably on a 20-minute dive but, with most of the dive being at 40m, you can expect a good 20 minutes’ decompression.

Diesel-electric overtaken by steam

It would have been little consolation to the crew of the Belgian coaster Turquoise to know that they had been sunk by an experimental steam gunboat of Britain’s Coastal Forces, writes Kendall McDonald.

Turquoise was a legitimate target, because this small vessel was armed and steaming along the Normandy coast as part of a German convoy on 19 June, 1942.

That’s when British torpedo-boats attacked. HMS Steam Gun Boat No 7 fired two torpedoes at her, one of which scored a direct hit.

Turquoise was 50m long with a beam of 10.5m, and had been built by John Cockerhill of Antwerp in 1932 for the Ostend-to-Tilbury run. She had been captured by German troops in Ostend when Belgium was invaded in 1940 and put to work by German Naval Command soon afterwards.

Steam Gun Boat No 7 had little time in which to celebrate her success, because she in turn was sunk by German E-boats later the same day. SGB-7 was the only war casualty of this experimental class of fast steam gunboats, of which nine were designed but only seven completed.

Towards the end of the war they were used as fast minesweepers. They were all 198 tons, 44m long with a beam of 6m. Their steam turbines could give them a speed of more than 30 knots.

Their armament consisted of one 3in gun, two 20mm AA guns and two 18in bow torpedo-tubes. The wreck of SGB-7 can be dived 11 miles east of St Vaast-la-Hougue in 30m.

With thanks to Mike, Penny, and Giles Rowley, Alex Poole and members of Bloxwich Sub-Aqua Club

Appeared in Diver, July 2001


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