Tech Talk

Explaining the Hogarthian Set-up

Hogarthian…to some a religion, interesting to some, yet most divers have never heard of it. Who is Hogarth after all? By Peter Herbst

William (Bill) Hogarth Maine is a cave dive,r and in the late 1980s he developed a system and a philosophy that still carries his name today. By looking at diving legends such as Scheck Exley, and combing their approaches with what the North Florida cave divers were doing at the time, he developed his ‘safer and more efficient’ philosophy.

Diving at Ginnie Springs

Ginnie Springs, located three hours drive north of St. Petersburg/Tampa Bay, West Coast Florida, is where you will find beautiful springs in over 200 wooded acres along the banks of the Santa Fe River. This is where you will find Manatees and underground cave systems that spread like a spider’s web for kilometres. By Celia Coleman.ginnie springs 800 kb

Instructor logbook Tech

Technical diving is a sensitive topic, not only for those who practise it but also for those who are misinformed about what technical diving really is. These people include fellow divers and family members. One thing is certain... technical diving is a step above the norm and I feel that in some aspects it is safer than recreational diving. I once heard someone say that with technical diving you challenge yourself, and in recreational or sport diving you amuse yourself. It depends on the diver I suppose. 

Breathing oxygen at elevated partial pressures

Breathing oxygen at elevated partial pressures

Pulmonary oxygen toxicity and Central Nervous System (CNS) oxygen toxicity – what is it and why is it important? By Pieter Venter

tech13When divers submerge themselves in the world of technical diving they also enter a world of new concepts and dangers often explained by theories derived from empirical data and strong emotional opinions. Without boring you with graphs, mathematics and reaction kinetics, two such concepts relate to the breathing of oxygen at elevated partial pressures.

Where does helium come from?

Helium is formed when the nuclear decay of isotopes deep in the earths crust takes place. Sound confusing? Then read on.

The atmosphere around us only contains five parts per million of helium and that makes it too low to recover. Currently helium comes from natural gas and this seems to be the only economically viable source for the moment. It is captured with the natural gas in a porous rock formation years ago and when the natural gas is withdrawn the helium is also released from the natural gas reservoir. The natural gas – mainly methane – contains 0,5% or 5 000 ppm. This makes the recovery of helium more economical.