Following training guidelines and conservatively planning our dives can reduce our risk somewhat, but learning how oxygen toxicity affects us and how we can prevent it can mean the difference between a fun dive and one that ends in injury. Push back against complacency and unquestioning acceptance of common practices—understand the effect of oxygen on your body before you plan your next dive.
Modern discussion has led to a wide variety of recommendations on the topic from a number of sources, leading to some confusion. While some agencies and physicians recommend diving conservatively with a known PFO, others recommend surgical closure, and still others advise that there may not be a benefit to closure and that divers should just be aware of their condition.
Marine mammals are not above the physical principles and processes that lead to bubble formation in tissues following decompression. Scientists once thought that diving marine mammals were immune from decompression sickness, but beached whales have been found to have gas bubbles in their tissues—a sign of the bends. In any case, how some marine mammals and turtles can repeatedly dive as deep and as long as they do has perplexed scientists for a very long time.
A recent study, published in The Journal of Physiology, shows that acute oral intake of antioxidants Vitamin C and E prior to a scuba dive can reduce alterations in cardiovascular function that are caused by a single air dive.
A group of professional divers were studied before and after a moderate scuba dive to a depth of 30 meters for 30 minutes, similar to those enjoyed by countless recreational divers.
The change in the physical behavior of gases at elevated pressures and in the hyperbaric environment itself exposes the human body to various stressors. This article—which will be presented in two parts—discusses inert gas narcosis (ING) and how it affects the diver, the mechanism behind narcosis, and methods used in order to ameliorate the negative impact of narcosis on divers.
It is estimated that approximately seven million divers are active worldwide and 500,000 new divers are training annually . Moreover, professional divers actively carry out diving operations for the purposes of commercial, scientific or military diving. The underwater environment is unique and any exposure to it presents a number of stresses to the human system.
Samuel H. ‘doc’ Gruber began studying sharks in 1961, perhaps before any other scientist had done full-time research on a living shark. During his long career, he founded the Bimini Biological Shark Lab, the Shark Specialist Group of the International Union for the Conservation of Nature, (IUCN), a United Nations organization based in Switzerland, and the American Elasmobranch Society.
Goliath grouper, or Epinephelus itajara, are the subject of strong opinions and divided emotions. Divers love to see these mammoth fish; underwater hunters denounce them as competitors, or covet them as outsized trophies; fishermen are just itching for a policy change that allows harvest; and regulatory bodies seem constantly poised to rescind long-term protection in favor of short-term exploitation.