You can dive anywhere along the beach at Porthkerris, but the interesting reef is the group of rocks just off the point at the old MoD range station. Entry is from the small strand separated from the main beach by an enormous rock. Standing on this beach and looking out, the reef breaks the surface 50-100m offshore (depending on the tide) and runs northwards to the point, where it ends with the largest rock of the reef.
     Apart from a couple of dives in a quarry, Porthkerris is where I made my first open-water dive. Shivering in the last week of March, I survived about 30 minutes dressed in a Cousteau classic wetsuit and repeated the dive several times that week.
     On the following years trip I was warm in a drysuit and helped take the next batch of novice divers in. The year after that, I organised the trip. Without counting logbook pages in detail, I would guess I have made more than 200 dives on the Porthkerris reef and still enjoy it every now and then.
     I am sure there are local divers who have made many more dives there, dropping in for a quick dip after work.
     So is this site magic or am I just getting nostalgic Located on the east side of the Lizard peninsula, Porthkerris is sheltered from the prevailing south-westerly weather. When a westerly gale is hammering the Atlantic coastline, the reef is calm.
     Even in an easterly sea, diving might still be possible. As the tide recedes, the reef offers greater protection to the small lagoon behind it. A few hours after high tide a strip of shingle leading to the narrow beach below the MoD station is exposed.
     The sea has to be pretty horrendous before it becomes impossible to enter and exit the water at low tide, and the viz will have been reduced to zero long before that.
     Under most conditions, Porthkerris is an easy dive. Drive up, carry your gear down a stone slope, put it on, take a compass bearing on the rock at the south end of the reef, slop into the water and swim out along the seabed.
     The only difficult part is descending the stone slope, especially if its wet and slippery. The dive centre has fitted a rope handrail, but perversely I used to find it easier before it was there. There is a natural zig-zag route down the rocks but the hand-rail leads you straight down.
     Under water, the shingle beach shelves down to rows of small rocks and kelp beneath the low-water mark. You will come to a shingle bowl just inside the reef, a popular spot for gathering a training group round and doing those initial static exercises.
     To get to the seaward side of the reef, you can go round the south end of the rock or through a gully that separates it from the rest of the reef. Either way, there are small sections of wall with anemones, hydroids, tunicates and dead mens fingers.
     Heading north along the seaward side, the first cut back into the reef is an obvious shingle-floored gully that goes a fair way in and ends in a cauldron with almost vertical walls. Vertical cracks in the walls are well worth investigating as, in addition to the usual shrimps and blennies, conger eels can be found in the larger cracks.
     A little further on, another cut starts a few metres up the slope of the reef and ends in a shallower rocky bowl that seems to collect dead kelp.
     Continuing north, stay a few metres up the reef rather than following the seabed. The next highlight is a large circular scour hole, followed by a 45 overhanging rock face. Sheltered from sunlight and protected from scouring, this has some of the best anemones and dead mens fingers on the reef.
     After this, a wide wedge cut into the reef ends in a short gully with a boulder across its entrance to make a chimney cave. The hole in the roof is easy enough to fit through with a single cylinder and pony on, though I wouldnt attempt it with a twin-set or rebreather.
     The reef then turns out to sea, where another steep wall is covered in small jewel anemones. This is the deepest point on the reef, with the seabed at 18m at high tide.
     To complete the dive, either retrace your path back round the south end of the reef or, below mid-tide, complete the circuit and exit at the beach under the MoD station.

Looking for crabs and shrimps in a crack in the rock at Porthkerris

a velvet swimming crab hides in a crack

finning through the gap in the south end of the reef


GETTING THEREFrom Helston take the A3083 towards Lizard Point and turn left on to the B3293 to St Keverne immediately after passing RNAS Culdrose. From the square in St Keverne, turn left for Porthallow. Follow the winding road for a couple of miles until the road for Porthkerris splits to the right, on a sharp left bend. About 150m further on, Porthkerris is signposted at a left turn which winds between fields and down a steep hill.

AIR:Porthkerris Dive Centre, 01326 280620. Dive Action, St Keverne, 01326 280719.

ACCOMODATION:Many local camping and caravan sites. Holiday cottages, B&B and pub accommodation also available. Helston tourist information, 01326 565431.

FURTHER INFORMATION:Admiralty Chart 154, Approaches to Falmouth. OS Map 204, Truro, Falmouth and Surrounding Area. Diver Guide - Dive South Cornwall by Richard Larn. On the Internet try Welcome.html.