This tour is a double treat, as JOHN LIDDIARD samples two wrecks rolled into one South-west dive site suitable for all levels of diving. Illustration by MAX ELLIS.
TO CELEBRATE THE CONCLUSION OF OUR FIRST CENTURY OF WRECK TOURS, we not only have a new look but two for one.
Two wrecks in one tour, that is, and two wrecks in one dive. They are the Hathor and Plympton in the Scilly Isles, in that order because Hathor dominates the site, resting across and obscuring much of Plympton.
In 1909 the Plympton drove onto the southernmost pinnacle of Lethegus Rocks from the south-east, initially coming to rest almost upright on the rocks, subsequently capsizing and later rolling down the reef to break up upside-down.
Eleven years later, in December 1920, the larger Hathor was under tow towards Portland when storms caused the towing tugs to cast her loose. She was swept sternfirst onto the same pinnacle of Lethegus from the south-west, coming to rest across the Plympton.
When you consider that the Plympton is mostly squashed beneath the Hathor, it's more like one-and-a-bit wrecks that we are actually touring.
Our tour begins in a gully on the south-east side of the rock that brought both wrecks to grief, where the propeller-shaft of the Hathor breaks at a depth of 20m (1).
The intact section of shaft leads towards the stern while, in the opposite direction, below the end of the shaft, sections of crankshaft and pistons from the Hathor‘s engine are sprawled across the bottom of the gully (2).
Continuing in a seaward direction, the line of the wreck is fairly obvious and easy to follow. Forward of the engine are the Hathor‘s boilers (3). Rather than linger, it's worth continuing forward and down at a reasonable pace to get the deepest part of the dive out of the way first.
As the reef drops, the way is marked by a section of hold hatch coaming, then a deck plate with a cargo winch still mounted (4) at a depth of 28m.
Following along the port side of the deck, there is a second cargo winch (5) and a pair of bollards at the edge of the deck.
Here our route leaves the Hathor and drops over the side to the seabed at 35m, where the tail section of the Plympton‘s propeller shaft emerges from below the Hathor‘s hull (6). This shaft leads into a short section of keel, followed by the propeller cut-out with the Plympton‘s iron propeller still in place. A couple of metres out from this, the Plympton‘s rudder lies flat on the sand (7). Now heading back towards the Hathor, the top of the forward mast and a pair of derricks (8) stick out from the general outline of the hull.
The hull of the Hathor is now almost flat to a level seabed until the bow, which has fallen to port. The break where the bow has tipped over provides easy access inside, and reveals some colourful anemones.
The anchor winch (9) has fallen from the deck, upside down below its mounting-plate, with steel tubes that would have guided the chain standing above it.
The tip of the bow is at 48m, with one of the Hathor‘s anchors standing against it on one side (10). Above the anchor, chain leads out from the hawse pipe on the upper starboard face of the bow.
Having followed mostly the port side of the wreck out, our route is biased towards starboard heading back to shallower water. The mast we passed earlier lies across the wreck, followed by a cargo winch (11).
As the depth shallows, looking over the starboard side of the Hathor will reveal the upturned, squashed and broken hull of the Plympton (12), where it has fallen along the other face of the rock. From here, a dive could continue on to the bow (13), but having been deep to the bow of the Hathor, a shallower and more interesting route is to continue on this wreck to the stern.
As the broken hull of the Hathor ascends the face of the rock, another boiler is orientated down along the wreck (14) to give a total of four. The Hathor is listed as having two, so why four?
Could the extra boilers come from the Plympton, which also had two? It's an amusing idea, but there is no way that they could have ended up on the Hathor‘s hull. They are squashed and broken below.
Did a third, unidentified wreck become involved? Apart from the boilers, there are no signs of wreckage that cannot be easily fitted in as part of the Plympton or Hathor.
The boiler (14) has a slightly different look to the two behind it, though this could be because they have rolled differently. More likely, I think, is that the Hathor had a pair of double-ended boilers, each built as two ‘almost-boilers', back to back.
At 7060 tons, Hathor was big enough to use that much steam. As the wreck broke, the double-ended boilers came apart and now look like four smaller boilers.
Now behind the boilers, our route crosses our starting point, where the propeller shaft is broken. The shaft leads back along the side of the rock into an intact section of tunnel (15).
From the end of this, the Hathor‘s spare propeller (16) can be found at the bottom of the gully at 24m. The general wreckage breaks at this point, though the propshaft leads further back before ending above a ridge of rock at 16m (17).
This gives the general direction to continue to the stern, descending again to 22m to a pile of chain (18), then a small derrick and a curved section of the stern railing (19). I suspect that as Hathor sank it came to a partial rest across this ridge. As the stern parted from the rest of the wreck, the propshaft was pulled out to remain with the forward portion of wreckage.
The railing continues round the stern past the steering engine (20), pushed up as the stern settled over the rudder-shaft, then ends by the broken parts of a winch (21), showing that the stern had turned slightly, relative to the general direction of the ship as it settled.
If there is no groundswell, one possibility for ascending is to head back to our starting point and ascend the rocks.
However, even on the calmest day there is likely to be a fair groundswell, so longer decompressions will be both safer and more comfortable on a delayed SMB.
Which brings us to the end of our first century of Wreck Tours. No one knows how many shipwrecks there are around the UK. Experts generally agree that there are more than 100,000.
That leaves 99.9% to go, and keeps me in a job for the next 8332 years.
Thanks to Richard Ross and Tim Walsh.
PLYMPTON, cargo steamer, BUILT 1893, SUNK 1909
HATHOR, cargo steamer, BUILT 1912, SUNK 1920
It's not often that you can explore two wrecks that really are one on top of the other.
But the Plympton and the Hathor on the Lethegus Rocks off St Agnes in the Scilly Isles provide exactly that kind of double-decker, writes Kendall McDonald.
First to sink was the 2869-ton steamer Plympton, built by Furness Withy in West Hartlepool. The single-screw ship was powered by three-cylinder triple-expansion engines with two boilers giving her 256hp. She was 314ft long with a beam of 40ft.
She was captained by Alexander Stewart with a crew of 24 and one passenger when she called at Falmouth from Rosario, Argentina. There she received orders to take her cargo of 4100 tons of maize in bags on to Dublin and discharge it there.
At midnight on 13 August, 1909, she ran into dense fog that lasted throughout the following day. Stewart knew he was in trouble.
The lead was used at short intervals and the siren sounded almost continuously. From 4am on 14 August, Captain Stewart set up a listening watch, with all hands on deck striving to hear the Bishop Rock foghorn. They still hadn't heard it when the Plympton ran on to Lethegus Reef, filled with water and was abandoned. The crew and passengers landed safely on St Agnes.
Once the islanders were satisfied that all were safe, they set about the ancient Scilly practice of stripping the wreck, which they found hard aground by the bow. However, while they worked the Plympton rose with the flood tide and, without warning, capsized and sank. Two men who were below were drowned.
Eleven years later, on 2 December, 1920, a bigger ship sank on top of the Plympton. The 7060-ton German Hathor was 465ft long with a beam of 60ft, built in 1912 with 482hp triple-expansion engines and two boilers. She was interned in Chile during WW1, when her main engine was neglected and was considered very suspect.
Despite this, after the Armistice she sailed for Portland with a full cargo of nitrate of soda and oil cake, but her engine broke down off the Azores.
She was taken in tow by two tugs, which lost her twice when the hawsers parted, and finally became unmanageable off the Scilly Isles on 1 December, 1920. The tow was slipped off St Agnes. Hathor stranded and finally sank to mingle with the wreck of the Plympton.
GETTING THERE: The Scillonian sails daily from Penzance, 01736 334220. Alternatively fly from Land's End with Skybus, 08457 105555, or by helicopter from Penzance, 01736 363871. For a group with diving kit, a freight container can be booked for the Scillonian.
TIDES: The current is never strong enough to prevent diving, even though it does funnel between the rocks in places, being strongest just before high water St Mary's.
HOW TO FIND IT: The Plympton and Hathor lie against Lethegus Rocks to the south of the island of St Agnes. GPS co-ordinates for the southernmost pinnacle of the rocks are 49 52.85N, 6 20.85W (degrees, minutes and decimals). This rises to a depth of 1.2m and the start point for our dive on the Hathor is to the south-east of this, as the rock drops into
QUALIFICATIONS: The variation in depth makes these wrecks suitable for divers wanting to build up their depth experience without committing to a rectangular profile dive.
LAUNCHING: It's a long way from the slip at Penzance, but the journey is feasible for a large RIB in good sea conditions, especially if the divers take the ferry.
FURTHER INFORMATION: Admiralty Chart 34, Isles of Scilly. St Mary's Road. Ordnance Survey Explorer Map 101, Isles of Scilly. Dive the Isles of Scilly and North Cornwall, by Richard Larn and David McBride. Shipwrecks Around the Isles of Scilly, Gibsons of Scilly. Isles of Scilly tourist information.
PROS: Two nice wrecks that provide diving covering the usual spread of dive club experience.
CONS: Exposed to the South-west.
DEPTH: 20-35m – 35-45m
Appeared in DIVER June 2007