Anywhere else along the south coast and Logan Rock would be a dive that everyone raves about, but sheltered behind the southern side of the Land's End peninsular it is somewhat overshadowed by such famous neighbours as Longships, Wolf Rock and the Runnel Stone.
Although the group I often dive it with call this site Logan Rock, Logan Rock is actually a huge granite stone perched precariously on the headland above. The Admiralty chart just marks the rock with no name, the Ordnance Survey map calls it Gamper, and local skipper Bill Bowen refers to it simply as "The Island".
Logan is actually the old Cornish word used to refer to a rocking stone, and the 60 ton Logan Rock used to be the most famous rocking stone in Cornwall. Only the slightest push would set it wobbling.
This came to an end in April 1824 when Lieutenant Goldsmith, in charge of a Royal Navy cutter placing a buoy on the Runnel Stone, ventured ashore and with 8 of his men levered Logan Rock off the cliff and into the sea. His punishment for this act of vandalism was to replace the rock at his own expense, a task which was finally completed in November 1824 at a cost of £130, though it could not be balanced so as to rock any more.
Anyway, back to the dive. Tucked into the bay behind the headland is a square sided rock that is almost large enough to be called a small island. As long as the wind isn't coming too far round to the south there is some shelter from the headland, and whatever the wind there is always some shelter from the rock itself.
Wind and sea permitting, I like to start a dive on the east side of the rock, rolling in about half way along. The wall drops almost vertically to 10 metres at the north end and 15 metres at the south end.
For a beginner this wall is probably enough for a dive concentrating on the macro life with jewel anemones of all colours and the wrasse and pollack that patrol along the wall.
The north end of the rock drops in short shelves to a sandy patch at about 10 metres, a convenient spot for getting some kneel on the bottom training exercises out of the way.
The wall doesn't end cleanly. The base of the wall is guarded by large tumbled boulders providing some interesting overhangs and boulder caves. To get a mental picture, think of the boulders beneath the cliffs on the shore line, but on a scale large enough to swim through the gaps.
South of the rock the boulder caves continue deeper. All are stable with obvious exits, so an experienced diver who is into holes can have a great time wriggling along, linking caves and cracks together, staying inside for most of the dive, though you will need a fairly minimal set of equipment to get through the tighter cracks.
Occasionally a flat plateau of granite and sand gives a false impression that the interesting terrain is coming to an end, only to drop away onto another area of boulders and crevasses, with the big boulders eventually running out between 35 and 40 metres.
So having covered the possibilities for beginners and experienced divers, the terrain between nicely covers the in between levels of diving experience.
As with the wall, every vertical and overhanging surfaces of the boulders are covered in jewel anemones with the odd cluster of dead men's fingers as you get deeper.
Shine a light into some of the tighter nooks and crannies and there are plenty of crabs, the occasional lobster and a conger eel or two. Horizontal surfaces are also home to occasional big yellow boring sponges and gorgonian sea fans. Wrasse are everywhere and pollack can be found hovering above some exposed corners. I have even seen the occasional John Dory at the fringe of the kelp line.
The west side of the rock is generally shallower with a boulder strewn seabed levelling out at 20 metres and blending into the general coastline profile. There are one or two exceptions, but generally the rocks on this side are too small to provide cracks big enough to swim through.
Later in the season the hydroids and kelp are host to rampant swarms of nudibranchs and during the summer plankton blooms it is not unusual to find basking sharks circling the rock while cormorants worship the sun above.