On the October long weekend in 1972, a group of four divers who had been diving with a large club in the area decided to stay behind for one more dive after all the others left, and chose a cave that none of them had dived in before. The cave was not well-known even to local divers, but the few who knew of it condemned it as a "mud hole". The cave's name is Alleyns Cave.

The decision was made at some point during the preparations not to use the guideline that one of the divers had brought with him, for the reasons that:

• "the water was crystal clear"
• "the water looked fairly shallow"
• "they would just go for a quick look around"
• the group did not realise that the hole contained an under-water cave with severe silting conditions.

At a depth of about four metres the party left the daylight section and passed into a dark chamber, through a small side tunnel that allowed only one person at a time to slip through with all their cave diving equipment on. Without a guideline this proved fatal. In the words of the only survivor, the dark chamber transformed itself from a clear room to impenetrable blackness within minutes. From this point, tragedy was inevitable.

The group of divers became separated in the silt as they had no line to link them together. They bumped into each other as they swam around, totally disorientated and unable to see their own torches in front of their facemasks. One diver survived. With almost his last gasp of air left, he swam past the exit tunnel and out through it into daylight and safety, where he remained, tapping his tanks to attract the attention of the others. His three companions drowned still trying to find their way out.

During the recovery operation, two of the divers' bodies were found at the opposite end of the dark chamber in a small tunnel of the same size as the exit tunnel which was, however, a blind one. Brave attempts were made by the only survivor to assist his companions during the underwater scramble in the chamber but he could not save them. Thus with the loss of three lives and very nearly a fourth, the necessity of guidelines in cave diving was illustrated. The experience of all the party, 15 years diving, 2 years, 2 years, and 18 months respectively, was still not enough to save them from a situation which was hazardous, but should not have been fatal. The loss of life was attributed to the inability of the team to assess the real hazards of their dive before commencing, and it is clear that their lack of much actual cave diving training and experience with silt outs was the reason the tragedy occurred.

Accident Analysis
Cause of Death - drowning after running out of air
Major Contributing Factors - inadequate training, failing to run a continuous guideline

More information on Alleyns Cave

Alleyns Cave Map | Credit: Peter Horne