08 April, 2009

Here is a Blog to be Watched!

For all of those out there who are intent and determined to make a difference in the race to save Sharks and with them vital elements of the very foundations of our living environment here is a blog and organization to be watched and followed.
Just click on the logo above!

What is Trimix?

The following post and any pictures used in this post originally appeared on DivingAnarchy.info.

DivingAnarchy.info and Diaries of a Frog Man have recently entered into a post swapping agreement where posts which are deemed of relevance to the diving community are shared / swapped to further improve access and distribution to relevant content.


Article by: Jim Cobb
Trimix is a combination of oxygen, helium and nitrogen. The idea behind trimix is to displace nitrogen with helium so that you can avoid the drawbacks of breathing high partial pressures of nitrogen.
Commercial divers omit nitrogen entirely for mid-range depths, using helium/oxygen mixtures called heliox. While certainly doable for tech divers, the logistics and costs are usually beyond most sport/tech divers capability.
For mixes in the deeper ranges, the required 02 content of your mix drops to the point that you can mix helium and air, called heliair, and not have to add 02.
To bring the advantages of replacing nitrogen with helium to every day sport/tech divers, it is advantageous to use partial pressure fills of oxygen and helium and then to top off with air.
The voodoo surrounding trimix
There is a misconception about trimix. Trimix is frequently promoted as the holy grail of scuba diving, so horrifyingly complex that you must take 4-8 levels of training before you can use it. In reality mixing a tank of trimix is no more complex than mixing a tank of nitrox.
What is complex and potentially dangerous is diving to extreme depths using multiple bottles of different mixes of gas, where choosing the wrong regulator can end your life in a hurry.
But it is possible to create a normoxic tank of trimix and treat it similar to air, without multiple mixes, bottles and other complexities, and enjoy the benefits of helium.
A fable about trimix is that you can't breath it on the surface. Generally speaking, the human body can handle lowered 02 percentages down to 16%. So, if you did a 17% mix, you can breath it as long as you want without fear of hypoxia. The breathability of a mix is solely dependant on it's 02 percentage, helium is complete inert and does not figure in.
Why use trimix?
The air we breath is composed of about 20.9% oxygen, 79.1% nitrogen and .033% carbon dioxide plus various inert trace gases. This is fine until we start breathing air under water. As we go deeper the partial pressures of these gases increase and we start suffering from their side effects.
Side effects of nitrogen include:
Narcosis- This is a mental function imparement which ranges from a mild euphoric feeling (60'-90'), slowing of mental activity (100'-130'), memory imparment and task fixation (140'-160') tingling in lips, legs and feet, severe drop in intellectual capacity (170'-200'), Voice reverberation, stupor and a sense of impending doom (200'+).
Bends- Nitrogen absorbed into tissues and fluids of the body reverting into gas bubbles.
Physiological- Damage to tissues leading to domino effects on immune system.
What about Nitrox?
Nitrox is an attempt to replace nitrogen with oxygen. Oxygen is metabolized by our bodies, so it is not absorbed into the tissue. Adding oxygen effectively reduces your nitrogen uptake, but there are some problems:
Side effects of oxygen include:
Central nervous system toxicity- CNS causes a seizure which can prove fatal while underwater. Partial pressures of over 1.6 can be extremely dangerous. 1.4 should be considered the maximum for a working dive, and it is reasonable to use 1.1 or 1.2 as your standard.
Inflammation of lung tissue from long term exposure- You can calculate your exposure to minimize this, but reports are coming in from the field of "lung burn out" caused by high levels of 02 which are well under the standard limits.
So why helium?
Helium is a non-toxic, colorless, odorless, tasteless, inert, lightweight and nonexplosive gas. To quote George Irvine head of the WKPP: "Helium is our friend".
Advantages of helium:
-Narcotic effects are nil.
-Due to its lower density, breathing resistance at depth is significantly reduced.
-Helium off-gasses rapidly and it does not enter slow tissues as readily as nitrogen.
Disadvantages of helium:
-Helium conducts heat 5 times faster than air.
-Hyperbaric arthralgia, an arthritic-like stiffness, can occur during descent with some divers.
Helium has been used for diving as far back as 1938. The first true test of heliox diving was the rescue of the submarine Squalus in 1939 in 240 fsw. Since then helium has been used in dives to more than 2000 fsw.
As helium is less dense than nitrogen, it enters and leaves the tissues faster than nitrogen. Paradoxically helium requires a little more decom time with short dives than air, but less decom time on long dives than air. The key to using helium is slow descents and slow ascents. Additional deep stops are required when ascending on helium mixes.
Due to helium's ability to leave tissues rapidly, having 2 or more stages, for example 50% nitrox and 100% O2, allows you to off-gas helium faster than you could nitrogen.
There is a situation which can occur in depths past 400ft. called High Pressure Neurological Syndrome (HPNS). This manifests itself with tremors, muscle twitching and coordination difficulties. Adding a small amount of nitrogen to your mix can alleviate these symptoms. But then, what are you doing down there, anyway?
Go ahead and use it!
Helium and diving were made for each other. You don't have to be a super tech diver to enjoy the benefits of helium. Breathing high partial pressures of Nitrogen is dangerous and hard on the body, so why do it? Replacing nitrogen with helium is a reasonable thing to do for single tank dives as shallow as 100'. What helium does for the 140-170 foot range (previously "deep air") is nothing short of miraculous. You remember the dive, you perform well under stress and you feel better after the dive.
Why you should not do deep air, click for the infamous AquaCorps Wah Wah article.
Deep air is dead! Long Live Trimix!

Nothing More Personal than a Wetsuit

The following post and any pictures used in this post originally appeared on DivingAnarchy.info.

DivingAnarchy.info and Diaries of a Frog Man have recently entered into a post swapping agreement where posts which are deemed of relevance to the diving community are shared / swapped to further improve access and distribution to relevant content.

When my partner started diving and got her OW certification we were looking into buying some personal scubagear.
At this stage we really didn’t know where diving would take her and how she would take on living but we knew that the purchase of a wetsuit would be a responsible expense as wetsuits are multi use items; swimming, snorkeling, surfing etc. A good wetsuit lasts a long way and diving in the winter in a bad fitting rental suit can put you off for a long time…

Two the most important things when it comes to wetsuits are warmth and fit. Warmth is determent by the thickness of the neoprene. Are you going swimming, snorkeling and diving in the tropics or will you go somewhere where the water is really cold? The other thing is the fit. If your wetsuit is to big it won’t keep you warm no matter what, so the right fit is essential.
To make the right purchase you need to understand how a wet suit works.
Wet suits are basically made from neoprene, which is a highly porous material that contains millions of tiny little bubbles. Neoprene uses the nitrogen bubbles to create a barrier of insulating gas between the water around you and your body. A thin layer of water enters this barrier and warms up by your body temperature. As you reach greater depths, the suit starts getting thinner as the bubbles compress. Your buoyancy becomes more negative and the exchange between water trapped between your skin and your wetsuit exchanges more easy with the water outside as the wetsuit becomes thinner and therefore loses some of the tight fit.

Water temperatures vary around the world. And they change with the seasons. It really depends on the location you choose as well as the time of the year. Your choice of wet suit will also depend on whether you are a man or a woman.
The difference between men and women wetsuits is the shape. In general women should get thicker and warmer wetsuits because a women body has more surface area than man and therefore cools down faster. And generally speaking it is always better to have a wetsuit that is warmer since if you are too warm you can let some cold water in by pulling your neck seal but if you are cold you will soon have to leave the water.
A two-piece wetsuit is likely to keep you warmer than a one-piece wet suit. A two-piece wet suit has the benefit of double insulation around the groin and chest area. However, double the insulation also leads to greater restriction in movement and greater buoyancy, which would require you to carry more weight.

After you’ve determent the right kind of suit, look for one that fits your body like a glove. Better a bit to tight than void area’s that fill up with water and work like bellows when moving.

I personally dive in a combination of wetsuits. In the winter I wear the combination of 2 Scubapro Everflex 3 mill tight fitting suits with a 2 mill hooded vest in between. During spring and fall I wear 1 Everflex with the hooded vest underneath and in the summer a single Everflex keeps me warm and comfortable during several dives a day.
When wearing the full winter combination the suits sit uncomfortably tight at the surface but while diving the neoprene gets squeezed, loses some of its tightness and the combo feels great.

06 April, 2009

Seraya Secrets - the Secret is Out!!

In October 2003, world renowned underwater photojournalist, underwater magazine and book author and multiple winner of international underwater photo contests over several years Michael Aw revisited Bali on an extended field trip to observe and photograph changes to Bali’s known dive sites and discover new ones. At the time, Scuba Seraya Resort was a small, modest affair and a mere 3 years into making. Little was known of the dive site ‘just in front’. Michael visited, and had this to say:
“Sometimes, unexpectedly, one will stumble upon a gold mine and, if you are shortsighted, and I mean literally, you may even miss the opportunity. It was timely for us to visit Patrick Schwarz, a Swiss expat who had set up a small dive resort some three kilometers from Tulamben Bay, 10 minutes away from his beach front property. On my first dive, I blew off 132 frames, equivalent to 3.6 rolls of film in just 30 minutes. This new hot spot of critters is without a doubt among the best in the world, matching sites in Lembeh Strait (North Sulawesi) and Papua New Guinea. During one afternoon dive I recorded 41 species of nudibranch and flatworms, beating a personal record of 28 off Nudi Falls at Lembeh Strait. Minuscule orange and yellow frog fish are not uncommon; but one with transparent polka dot dorsal fins is a species that has yet to be published in any identification book and is not known to Dr. Gerry Allen, one of the world’s best known ichthyologists.
Of course, there are the usual suspects – Ghost pipefish, Bobbitt worms, Boxer crabs, octopus, Ornamental squid, Sand divers, Frogfishes, Stonefish, Sand eels, Sand anemones, tons and tons of strange Crab’s shrimps, Flat worms and I was fascinated to photograph one of the most exquisite psychedelic colored Tiger shrimp (Phylognathia ceratophthalma).
I was so impressed with this new hot-spot, which we now call Seraya Secrets after Patrick Schwarz’s resort, that of course I stayed to continue diving there for the next three days, abruptly putting an end to the live-aboard trip and my intention to circumnavigate the island of Bali. I am sure news will travel fast through cyberspace and hundreds of macro enthusiasts will land on Patrick’s doorstep in a flash to discover the critters of Seraya Secrets.
As I have learnt, Bali remains predictable – the island oozes with enchanting culture, the people are the most charming within a fabric of diverse culture in a country of 230 million, and the sea predictably promises surprise after surprise”.
News did travel fast indeed – as predicted by Michael Aw. Today, Seraya Secrets is a must dive mark on most diver’s itineraries to Tulamben, besides the other Tulamben ‘classic’ dive sites. Seraya Secrets even got its own dive flag marker on newer Bali maps and is automatically mentioned in all trip reports and articles to the area. The secret’s out – Seraya Secrets is ‘no secret no more’.
Michael Aw continues to visit regularly and he holds a week long digital underwater photography workshop at Scuba Seraya Resort once a year. What better way than to learn from the pro’s whilst having one of the world’s richest macro grounds at your doorstep!
Patrick Schwarz is a Dive Instructor and owner and founder of the Scuba Seraya Resort at Tulamben on Bali’s north-east coast. He has lived in Tulamben and dived and learned to love the underwater realm around Bali Since 1997 patrick@scubaseraya.com http://www.scubaseraya.com/

03 April, 2009

Act Now! Help Bring Sharkwater to China!

It's really important that you help us bring the award-winning documentary Sharkwater to China.
China is the largest consumer and trader of shark fins in the world, fueling the growing demand for shark fin soup that is destroying our oceans within our lifetime. Most Chinese consumers don’t know that shark fin soup contains shark, because the translation literally means, "fish wing soup".
Shark populations have dropped more than 90% in 30 years, destroying the most important ecosystem for our own survival. Conservation isn't just saving species and ecosystems, it's saving humans.
This is a huge consumer awareness issue that we have the power to change. We urgently need your help to create a Chinese version of Sharkwater that will target an audience of over300 million people. We can change the world, with your help.
WHAT YOU CAN DO:Donate now to the non-profit foundation SAVE THE BLUE that is working with us and WildAid to bring Sharkwater to China & receive a special custom-made tribal shark pendant, shirt or bag!
Wear your special shark pendant with pride to engage people in making shark conservation an international priority! It’s cool to save sharks!
Act Now & Donate to bring Sharkwater to China.
Thanks for helping us save sharks,Rob Stewart and the Sharkwater Teamhttp://clicktrack.onlineemailmarketing.com/i8-8vatvhft-ljcvq-2v5x-75EA117A--.clk