There is an almost endless choice of wreck and reef sites around Penzance, and the combination of Atlantic, Gulf Stream and river outfalls often results in impressive visibility and unusual sub-tropical marine life.
To experience the most exciting diving that this end of the country offers, you have to include a visit to the waters around Lands End.
As this area is very exposed, the effort will be wasted sometimes if the weather turns against you. However, it is well worth the risk of disappointment. And there are several more sheltered alternatives along the coast if the conditions are not quite right when you arrive on site.
For one of Cornwalls old favourites, head for Mounts Bay, which hides the remains of the wreck of the 2774 ton steamer Hellopes. She was on her way to the breakers yard carrying a cargo of coal that shifted in a fierce NNW gale, causing her to take on water and founder off Penzance on 29 December 1911.
The wreck now lies in 32-34m of water on her side with the hull relatively intact and the steel screw and rudder still in place.

Tides are not much of a problem except in spring, and the wreck is easily found on transits (talk to the locals) and echo sounder, as she stands up well from a sand and shale seabed at approximately 50 02 05N; 05 30 06W.
Not to be missed on a trip to this area is the infamous Runnel Stone, reputed to have wrecked more than 27 ships. The Stone is in fact an extensive area of reefs and pinnacles that had a surface-breaking rock until it was smashed away by the City of Westminster in 1923, inevitably causing her demise.
The reef area is open to the Atlantic and subjected to some exceptionally strong tides. Choose a neap tide and slack water in good weather conditions, and even then there is normally a healthy swell with which to contend.
Local knowledge is essential and the weather conditions can change quickly, so be prepared to turn back to more sheltered sites if necessary. However, when the conditions are right, the Stone is simply stunning.
The reef system boasts walls, gullies and plateaux supporting a wealth of marine life and may provide an encounter with sub-tropical visitors such as triggerfish and sunfish. Large shoals of mackerel, bass and pollack are common and show little fear of divers.
Among the rocks are the remains of numerous wrecks, in some cases so close or overlapping that it is difficult to tell which is which.
The largest is the City of Westminster, which lies on the south side of the Stone. Her remains include the bows and midships section in 20-25m, while her stern lies a little off the main reef in 50-55m and is consequently rarely dived.
Other wrecks close by are the Royal Fleet Auxiliary Moorview (1920), the Febrero (1863), the Lake Grafton (1920) and the Joshua Nicholson, all in depths of 15-25m.
The Runnel Stone offers something for everybody, with masses of wreckage and the alternative of adjacent spectacular drop-offs and gullies for photographers and marine-life enthusiasts.
 The visibility is generally very good, with 20m not uncommon, but watch out for the plankton bloom in late spring and early summer.
To make the most of a weekend visit to Cornwall, it is best to target a specific area that offers the right facilities and easy access to good diving.
Penzance, in the far west, is particularly well equipped, with a huge range of accommodation and a number of diving centres, as well as charter boats to satisfy all diving tastes.
Launching from Penzance accesses the coastal and offshore sites between Mounts Bay in the north-east to Lands End and the Longships in the south-west.
Penzance harbour has an excellent slipway for launching, with a large car park adjacent (fees charged for both). The slipway does dry on low water, but unless there is a large spring tide you can generally get in and out with a RIB an hour or so either side of low water.
The slip is used by all sorts of watersports enthusiasts, so in high season or over holiday weekends it is best to arrive early.
If you want to launch a little closer to Lands End, there is a slipway at Lamorna Cove. Its small car park gets very busy in summer, so arrive early. A launch fee is charged and a four-wheel drive is recommended for heavy boats, as the slipway is steep and the sand soft at low tide.
Alternatively, try Sennen Cove, which is a beach launch on the north coast, handy for the Longships Reef. It has a large car park, which gets busy in summer, and a four-wheel drive is a must for heavy boats.
The journey down to Penzance is much faster than you might expect. The road system in Devon and Cornwall has been substantially improved, particularly the A30, which is now a dual carriageway from Exeter to Penzance (a last short section in mid-Cornwall is due to open in 1998).
So the once-daunting journey time from, say, London, Birmingham or the home counties has now been cut to between four and six hours, making even Lands End accessible for just a weekend diving trip.
So with a little forward planning you can set off for the south-west on the promise of a good forecast on a Friday evening and enjoy two full days of diving before heading home on the Sunday. n
For more booking details on all these weekends see the classified advertisements on pages 106/7.


GETTING THERE: M4 or A303 from London, M5 from Birmingham joining A30 at Exeter for Penzance. Rail or coach to Penzance from various locations.
ACCOMMODATION: Wide range of hotels and bed and breakfasts in Penzance and other resorts. Mounts Bay Diving operates a guest house, 01736 752135.
DIVING: Undersea Adventures, 01736 333040, and Dive Action Diving Centre, 01326 280719, offer packages including accommodation; Trevair Campsite can provide air, nitrox and trimix, 01736 740647. Air and nitrox are available at Mounts Bay Diving (01736 752135) and Undersea Adventures.
CHARTER BOATS: Hardboat - Son Calou, 01736 752135; RIB - Cornish Diving Services in Falmouth, 01326 311265, RIB - Undersea Adventures at Long Rock, 01736 333040. Liveaboards - Mentor Maritime, 01872 862080; mv Maureen, 01803 835449; mv Chalutier, 01392 431841; Dunedin, 01548 842057; McGregor, 01503 263584.
LAUNCHING:Penzance - slipway; Lamorna Cove - slipway; Sennen Cove - beach launch; Porthgwarra, near Lands End - awkward beach launch so only for small boats.
WHO WILL ENJOY THE DIVING: All abilities catered for, but areas such as the Runnel Stone and Longships require experience, so bring correct safety equipment.
FOR NON-DIVERS: Wonderful beaches, cliff walks and activities for whole family.
FURTHER DETAILS: Penzance Tourist Information Centre, 01736 362207; Falmouth Coastguard, 01326 317575 (fax 01326 318342); Penzance BSAC, 01736 369213; Penzance Harbourmaster, 01736 366113; Lamorna Cove, 01736 731734.
PROS: Huge variety of dive sites to suit all abilities, with easy access. Wide range of accommodation and plenty of apres dive entertainment. Good location for divers with non-diving family.
CONS: High season will require some forward planning and perhaps an early rise for boat-handlers to ensure a clear launch, particularly if you are aiming to catch a tide.