Diving with non-air gas mixtures: Nitrox, Heliox, Trimix
WHAT IS NITROX?
Nitrox is a gas mixture of oxygen and nitrogen, but with a higher oxygen percentage than found in ordinary air. As a result of its higher oxygen concentration, the percentage of nitrogen in nitrox is always lower than in air. There are two standard mixtures of Nitrox recognized by NOAA for diving: Nitrox I and Nitrox II (see Table 1).
via Diving with non-air gas mixtures: Nitrox, Heliox, Trimix.
Diving Medicine Articles
OXTOX: If You Dive Nitrox You Should Know About OXTOX
DAN discusses the dangers of oxygen toxicity when using nitrox as a breathing gas
By Dr. E.D. Thalmann, DAN Assistant Medical Director; Captain, Medical Corps, U.S. Navy (retired)
It’s a fact: we need oxygen to live. It’s because of the way our cells use oxygen that we are able to breathe, exercise, and even think. In each of our cells, structures called mitochondria take the oxygen which diffuses in from our blood, disassemble it into its two component atoms (remember, oxygen – O2 – is composed of two oxygen atoms), and then hook some available hydrogen nuclei to them to form water.
via DAN Divers Alert Network : OXTOX: If You Dive Nitrox You Should Know About OXTOX.
MYSTIC, Conn.—A group of divers says it has found the wreckage of a schooner that collided with a steamship and sank in 1903 near Block Island, R.I.
Mark Munro of Griswold, Conn., said his Sound Underwater Survey group and the Baccala Wreck Divers began looking for the remains of the Jennie R. Dubois in 2002, searching a few times a year in an area that eventually stretched to 17 square miles.
The group positively identified the shipwreck in September 2007, but kept it a secret until Monday so more research could be done and others interested in the ship couldn’t claim the find, Munro said.
It was discovered about six miles southeast of Block Island in federal waters, he said.
“We were pretty elated,” Munro said Tuesday. “It was one of those projects that you were starting to wonder if you were really going to solve the mystery of what happened.”
The 2,227-ton, five-masted schooner, which was launched only 19 months before the collision, was named after the wife of a Rhode Island Supreme Court justice who owned stock in the company that built the ship, Holmes Shipbuilding Co. of Mystic.
Munro said the vessel, which cost $100,000 to build, was the largest ever built on Connecticut’s Mystic River. Jennie Dubois christened her namesake ship with a bottle of wine on Feb. 11, 1902, in a ceremony that attracted 6,000 people, Munro said.
The Jennie R. Dubois went down on Sept. 5, 1903, after colliding with the steamship Schoenfels in dense fog about seven miles southeast of Block Island. All 11 men aboard were rescued, Munro said.
A lot of people had looked for the wreckage over the years. Munro said it was difficult to find because the Army Corps of Engineers blasted the wreckage with dynamite in 1903 so it wouldn’t be a hazard to other ships.
“They were looking for something that would look like a schooner,” Munro said. “In this case, it was not what you would typically see at the bottom. It was spread out.”
Munro and his fellow divers were able to identify the shipwreck by its anchors, size and location, he said. They researched local newspapers, examined the national archives in Washington, looked at Mystic Seaport records and talked with Block Island residents.
Members of Sound Underwater Survey and the Baccala Wreck Divers plan to present their findings at the Mystic Yachting Center on Feb. 11, the 107th anniversary of the Jennie R. Dubois’ launch.
To view the complete article: http://www.bigbluetech.net/big-blue-tech-news/2008/12/24/divers-find-1903-shipwreck-block-island/
By Lukman Nul Hakim Mazlan
KOTA KINABALU, Dec 23 (Bernama) — Flashback to the 1960s and James Bond movie fans would definitely remember ‘Thunderball’ that starred Sean Connery.
This movie was about a group of terrorists that had hijacked a nuclear missile and hid it on the seabed.
That film had also featured underwater action scenes, which captivated the cinemagoers including that of a torpedo-shaped vehicle that moved swiftly under the sea.
Fast-forward to today, those who wish to experience to move faster during snorkeling or scuba diving, they could try a similar machine known as ‘Sea Doo Divers Propulsion Vehicle’ or DPV.
DPV is a vehicle-like equipment that assist a person to move faster either on the surface or under the sea.
It is ideal for those into snorkeling or scuba diving as this machine propels the person at a much faster speed as compared to the normal physical locomotion during these activities, hence conserving that person’s energy.
BORNEO DIVERS
For those who visit Pulau Mamutik, Tunku Abdul Rahman Marine Park, located some 25 minutes boat ride from Kota Kinabalu, they would have the opportunity to try out the DPV.
Borneo Divers and Sea Sports (Sabah) Sdn Bhd managing director, Clement Lee said the DPVs at the island were imported from the United States.
But the DPV is no stranger in Malaysia, he said.
“Others have brought in the DPVs from abroad for their personal use but we are the first company to import it.
“We aspire to make the DPV popular in Malaysia particularly among enthusiasts of snorkeling and scuba diving”, he told Bernama at Pulau Mamutik recently.
For first-timers, the DPV is not difficult to handle.
When using the DPV, it is like handling the steering wheel of a car. Just move it either to the left or right and the DVP would bring you to the desired direction.
DPV PRICE
Each DPV sells from RM900, depending on the engine power.
The motor-powered gear could last up to three hours and divers would have fun using it as the DPV allows faster movement and is less tiring to use.
Shamsul Bahrin Zainuzzaman, 32, a photographer with the Kuala Lumpur-based Gaya Travel Magazine, who had the opportunity to try out the DPV, said:
“Initially I was scared, not having confidence that this thing (DPV) could float but after getting the feel, I think I would want another go.
“Maybe the next time around, I would try it for scuba diving”, he said.
RESCUE WORK
Lee said the DPV could also be used to rescue someone who is in distress.
“Lets say that you want to rescue someone having difficulties about 500 metres from the beach. You could use the DPV to get to the person in a fast time”, he said.
However the DPV for recreation is not suitable for rescue work as there are other more suitable models and versions.
“There are other DPV versions that are suitable for rescue work. They are faster and high-powered”, said Lee.
Jinnifer Missi, Borneo Divers assistant manager, said the DPVs are also suitable for use by the Fire and Rescue Department apart from the police and other related services.
COURSES
Lee said the company allows the DVP to be leased for RM50-RM70 for a half hour session.
Day-long course at RM350-RM400 is also offered to those who wish to learn on how to handle the DPV.
“We would teach them how to use the machine under the sea and how to conserve power apart from the safety aspects”, he said.
However, a scuba diving license is needed before a person is allowed to use the DPV underwater.
At present, Borneo Divers has six of the DVPs but plans to have a total of 50 machines in the future.
More information on the DPV is available at Borneo Divers and Sea Sports (Sabah) Sdn Bhd, 088-222226.
– BERNAMA
To view this article: http://www.bernama.com/bernama/v5/newsindex.php?id=380003
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