Divernet
Waves permitting, I like to start a dive on the City of Westminster by dropping straight on top of the Runnel Stone rock (1) which caused the ships sinking. The slope of the reef is such that if there is any sort of a groundswell, waves build up and break as they cross the stone. RIBs have been flipped when they have got too close in a heavy swell, so take care.
Once under the surface, even in flat and calm conditions, there is a large surge on top of the Runnel Stone. A short southerly swim, using handfuls of kelp to help you along, brings you to a sludge-filled gully running from east to west (2).
Densely packed miniature plumose anemones in orange, cream, green and brown are everywhere. Huge ballan wrasse are busy selecting occasional morsels from the rock. A deep and smooth scour hole provides evidence of the raw energy of the sea.
In 1923, the City of Westminster broke in two on the Runnel Stone rock in heavy fog and sank. The wreck site is actually only the bow section which came to rest on top of a previous wreck, the Moorview. The sterns exact position is unknown, but is further out in about 50m of water.
Turning right along the gully, the first piece of wreckage appears - an enormous girder that stretches out from the end of the gully above the main part of the wreck. During the summer this girder is home to hundreds of nudibranchs - at least five different species have been counted in less than 1sq m.
At the end of the gully, drop to around 20m and turn left, to reveal a large section of hull lying propped against the rock (3). Underneath is a swim-through hole that brings you out at 26m (4), where the frames separating the double hull provide many interesting hiding places for conger eels and lobsters.
Crossing the wreck to the west, you pass a flattened tangle of girders and plates and the foot of a mast (5). The side of the wreck is only 2-3m above the seabed, with an open lattice of frames separating the double hull. Beneath these lies a floor of coarse granite sand and broken shell (6).
Turning left again for deeper water, a mast lies stretched across the sand at 28m, resting just short of a huge granite block (7). A large conger eel resides in a break in the mast and it is sometimes bold enough to come out and slither round visiting divers.
Following the mast back over the wreck, there is a fragment of deck plate with bollards sticking out (8). Ahead, on the right, a large winch comes into view (9). Turning along the wreck, gaps in the hull show through to the sand (10). A large anglerfish has been spotted here before, lying snoozing with his lure out and a grin from ear to ear.
By 35m the wreckage has mostly given way to sporadic bits of steel in a pair of sandy gullies which lead into even deeper water (11).
Moving back towards the Runnel Stone, another deck plate with bollards and bits of railings marks the edge of the Westminsters hull (12). If you want to ascend now, it is simple to follow the hull back to the rock, using the swim-through and girder from earlier as navigation aids.
If carrying on, I like to turn east along a steep wall at the south edge of the Runnel Stone (13) between 20m and 30m. As the wall starts to turn north (14) and form a wide gully between the Runnel Stone and Lee Mean, scattered broken plates and girders mark the remains of a steel-hulled sailing ship.
Eventually the east end of the narrow gully that splits the Runnel Stone is reached (15). The wreckage here is mostly from the small steamer Moorview.
Moving further north along the wall, a pair of anchors (16) lie wedged in a corner at 18m. The remains of the beacon - which used to be on top of the Runnel Stone until the City of Westminster destroyed it (see panel) - now lie tight in against the rock on the north side (17).
A shallow, kelp-filled gully (18) leading south-west at 14m marks the way to complete the circumnavigation. Even here there is so much debris that it is difficult to know if the kelp is attached to rocks or steel. An old fishermans tale suggests that there is no rock at the Runnel Stone, just an enormous pile of wrecked ships.
Back among the main body of wreckage, the first obvious landmark is a pair of broken boilers from the Moorview in about 20m of water (19). From the boilers, keeping the rocks on your left, you arrive back at the girder and gully from your descent and can take a much-needed decompression stop.
The route described makes a very long single dive. If tides and seas permit, it is worth breaking the route into sections and making several dives on the wreck, taking your time to explore one of the most spectacular dives in the South-west.


DRAMATIC ROCK SMASH  
When the City of Westminster ran into the Runnel Stone rock on 8 October, 1923, she hit it so hard that she knocked 6m off its top, writes Kendall McDonald. As a result, the Runnel Stone, which used to be visible at all states of tide, has never since been seen above water.
The 6094-ton ship was formerly the German Rudelsburg and was handed over to Britain as part of war reparations in 1919, at which point her name was changed.
As she made her way from Belfast to Rotterdam with 2400 tons of maize, she was running in and out of patches of fog. That fog became particularly dense as she approached Lands End and thicker still just before she struck the rock. Driving hard on, she tore huge holes in her bottom and ripped off her stern post. Number 1 and Number 2 holds started filling immediately and Captain Ring, who had his wife and daughter aboard, at once ordered the crew of 73 into the boats.
Both the Sennen and Penlee lifeboats soon appeared and rescued everyone without loss. Shortly afterwards, the 470ft-long City of Westminster slipped broken-backed down the side of the Runnelstone.












Divernet

Divernet
TIDES: Slack water is 1 hour before high water Penzance. On neap tides it can be slack enough to dive from 2 hours before high water until just after. On spring tides it is only really slack for 15 to 20 minutes. There is sometimes also a brief slack about 2 hours after high water Penzance, but dont count on it.

GETTING THERE: Follow the M5 to Exeter, then the A30 to Penzance.

DIVING AND AIR: Bill Bowen (01736 752135) runs the hard boat Son Calou from Penzance Pier and has a fast compressor.

LAUNCHING: The slip in Penzance harbour is wet for most of the tide. A slip at Lamorna cove is wet for a couple of hours either side of high tide. There is a slip at Sennen next to the lifeboat station, but the area can be very crowded with surfers and tourists. It is possible to launch across the beach at Sennen, but beware of soft sand, heavy surf and shallow reefs. Harbour fees are payable at all these slips.

ACCOMMODATION: There are many camp sites in the area, though not that cheap, and a wide range of B&Bs and hotels. Contact Penzance Tourist Information (01736 362207) for a list.

QUALIFICATIONS: A Sports Diver or equivalent accompanied by a suitably experienced leader could tackle this dive at slack water on a good neap tide.

FURTHER INFORMATION: Admiralty Chart 2345, Plans in SW Cornwall. Admiralty Chart 777, Lands End to Falmouth. Ordnance Survey Map 203, Lands End, The Lizard and The Isles of Scilly. Diver Guide: Dive South Cornwall by Richard Larn. Useful website: www.cornwall-online.co.uk/westcorn/penzance.htm.

PROS: A nice wreck in which to rummage and some spectacular life-covered walls for those who prefer marine biology. Often excellent visibility of 20m and above.

CONS: Very susceptible to weather and tide conditions.

Thanks to Colin Thornton, Bill Bowen and Mike & Sarah Phillips for their help.

HOW TO FIND IT: Go to the bell buoy 100m off shore and line up the two cones on the cliff tops above Gwennap Head. From the bell buoy follow this line in. The depth will jump from 35m to 15m, then to about 6m before dropping again to 20m. The 6m point is right above the rock. Be careful of the groundswell. You dont need a GPS to find the Runnel Stone, but the charted position is 50.1.33N, 5.40.33W (degrees, minutes and decimals). If dropping a shot, it is best to steer just west of Runnel Stone and drop it onto the wreck at 20-25m, letting the line drag back across the rock.