30 November 2006

Scuba Gear Part III - The Octopus

Now yesterday were on the subject of regulators and 1st stages and we'll keep that train of thought so lets travel from the regulator (2nd stage) back up the air hose to the first stage again. Yes here on the first stage this is where everything really happens isn't it? All these hoses coming together up here. This really is the party place in the SCUBA harness. Now for today's post we are going to jump onto a third air hose. This is a bright, easy to see, yellow one. Yeah that's right, Dorothy, we're going to follow the yellow brick road. Down we go now to our Octopus. Our little, or not so little, yellow regulator we share with our buddies when/if they run low on air.

Well, sadly, this piece of equipment I did not spend a whole lot of money on. Yeah if you are my buddy and you run out of air, it's not going to be as nice breathing on my octo as it was on your reg. But it should deliver the air just fine and we should both make it back to the surface a'ok.

I chose the Aqua Lung ABS. It can't be all that bad. It is made my Aqua Lung after all. And it received a "testers choice" award from Scuba Diving Magazine. Here are the features from Aqua Lung -

  • The New ABS Octopus combines excellent breathing performance with the benefits of a low profile body style.
  • Exceeds CE breathing requirements for regulators
  • Versatile design allows proper function when right side up or upside down
  • Unique 120° angle between hose and mouthpiece: This Aqua Lung innovation is ideal for giving your octopus to a buddy - will work in either right hand or left hand positions. No more sharp bends in the hose or upside down octopuses in the mouth
  • Custom quick-release mounting clip keeps the ABS properly located on the body at all times
  • 39" yellow hose easily distinguishes your ABS hose from your primary hose. This high visibility hose is easily spotted in case of an out-of-air emergency

29 November 2006

Scuba Gear Part II - The Regulator

Since I covered the computer console yesterday I will just follow our high pressure hose up to the first stage and down to the regulator. Man this was a hard one. I know at least 20 manufacturers of regs. Most companies have several different models in a vast range of price. It's really quite amazing the amount of features, types of material, and construction that goes into something which basically just delivers air. Hmmm, just delivers air. Did I really say that? Air is life! We need air! In all types of environments. Polluted, silty, cold, warm, under various pressures in a single dive. We need a regulator that delivers a nice breath of air with no moisture in it. We need regulators that deliver air sideways and upside down, with little effort, regardless of the volume of air were taking in under the increased pressure. And one that will allow oxygen enriched air, should we choose to do so.

Yeah can you imagine what it was like 20 - 30 years ago. When you put it in perspective we really have it made today. I'll quote Scuba Diving Magazine again from their article, How Much Should You Spend on a Regulator? They say,"How a regulator goes about delivering air--pistons or diaphragms, balanced or unbalanced first stages, adjustable or nonadjustable second stages--isn't as important today as it was 10 years ago. Credit clever engineers or blame clever lawyers, but today no company can afford to sell an underperforming regulator. Nearly all of them--regardless of price or design--will safely deliver all the air you'll need down to 130 feet and a good distance beyond. There are many regulators priced well under $300 that do the basic job and even some budget models that deliver as much air in extreme conditions as the most expensive ones." A note again that when I speak of regulators I speak also of the First Stages since they usually come together.

One of the big factors for me was cold water. You see while I prefer to dive in warm water environments I live here in the Pacific Northwest. I've dove here before and I know I will again. So do I buy a cold water regulator or not. You may know as air expands it gets colder and when it gets compressed it heats up. (Pump up a bike tire to it's maximum pressure and feel the pump hose afterwards. It's warm.) So you're in the cold water, chillin your air hose and as the air comes into the regulator it expands, thus making it more cold. There is the possibility that any moisture in there will form ice crystals and "freeze up" your reg. Not good. So they have "cold water" regs that get around this. Water below 50 is considered cold water for a regulator. I've dove around here in water between 43 and 60. So I opted for the one of these regs. Here are the specs from the Aqua Lung website -

The Titan LX Supreme is the cold-water version of the Titan LX and can be identified by the "snowflake" seen on the front of the case. It has all the same features as the Titan LX and additional cold-water features:

  • First stage environmental dry seal kit to prevent ice from forming in the first stage
  • Specifically adjusted to pass the stringent European Standards for cold-water regulator performance
  • Built-in heat exchanger
  • A mouthpiece lip shield for warmth in extreme cold
  • Proven Titan balanced diaphragm first stage.
  • Air Turbo System
  • Compact 1st stage design
  • Pneumatically-balanced compact, lightweight second stage maintains consistent ease of inhalation as tank pressure drops
  • Diver-controlled Venturi Adjustment Switch (VAS) reduces sensitivity to free flow on the surface and provides maximum airflow at depth
  • Exclusive Comfo-Bite™ mouthpiece virtually eliminates jaw fatigue
  • 4 low pressure ports and 1 high pressure port.
  • All ports angled for optimum hose position.
  • Compatible with EAN 40 right out of the box
Update - This reg and first stage worked wonderful over my Mexico trip. I noticed no difficulty breathing at depths up to 90 feet.

28 November 2006

Scuba Gear Part I - Computer Console

So I actually purchased my SCUBA gear. After reading a sea of articles, manufacturers websites ans some posting to the Northwest Dive Club about "cold water" regulators I finally made some decisions. It was tough. Each specific piece of gear seems to have an unlimited number of options and ranges of performance. But with all that comes greater and greater price tags. I'll post about each of the items I purchased over the next few days. Today we'll talk about the dive computer.

It's an Aeris Atmos 2 in a quick disconnect console with a compass, analog tank pressure gauge and dive knife on the back. Scuba Diving magazine's Scuba Lab gave it a Tester's Choice.

Overview -
Nitrox compatible (21-50%)
•PC downloadable, up to 255 dives
•Manual & water activation
•Audible alarm with flashing LED
•User-replaceable batteries
•User programmable alarms (ascent rate, max depth, PO2, N2, O2, dive time remaining, elapsed dive time, PO2)
•Advanced dive plan simulator
Desaturation countdown timer
•No-fly timer
•Depth to 330', 1st deco stop @ 60' Gauge mode to 399'
•Temperature (on the surface and at depth)
•Time and date stamps for log & download
•N2/O2 bar graphs
•Dive log

Check out a complete list of features, with descriptions, at the Aeris web site here - http://www.diveaeris.com/p_computers_atmos2_features.html

Update - While diving in Mexico this computer and console delivered all the information I needed. Easy to read and quite easy to use. I'm quite satisfied.

24 November 2006

Scuba Equipment

So it's been like 2 and 1/2 years since I first dove into this wonderful world of SCUBA and finally I may be getting my own equipment. It's really a Christmas gift from my wife but I have to pick it out. We are going to Cancun/Cozumel in February and she wants me to have my own kit. I always figured I would buy one piece at a time but she said I should just buy the full package. Who am I to argue? I'll post more once I purchase the stuff.

10 November 2006

American Accent?

I saw this on Dave's Beer Blog and I had to try it myself. Apparently this is my American "accent".

What American accent do you have?
Your Result: The Midland

"You have a Midland accent" is just another way of saying "you don't have an accent." You probably are from the Midland (Pennsylvania, southern Ohio, southern Indiana, southern Illinois, and Missouri) but then for all we know you could be from Florida or Charleston or one of those big southern cities like Atlanta or Dallas. You have a good voice for TV and radio.

The West
North Central
The South
The Inland North
The Northeast
What American accent do you have?
Take More Quizzes

07 November 2006

Diving one atmosphere ABOVE sea level.

This morning I read a great article in my Alert Diver Magazine. Alert Diver is put out by Divers Alert Network (DAN) to it's members. I highly recommend a DAN membership to anyone who is an active diver. DAN can be called anytime for advice on a dive emergency from anywhere in the world. They will help with transportation and can recommend the nearest hyperbaric chamber and/or hospital.

In the Article, Diving the USS Barometer, written by Richard D Vann, PH. D., DAN Vice President of Research, a man was messing around with his turtle pond. He filled a jar with water, raised the closed end above the surface of the pond and a fish swam up into the jar. This got him thinking. What if the jar were 10 feet in diameter, 60 feet long and filled with sea water? Suppose the open end were under the water and the closed end above sea level. What would be the pressure at sea level inside the jar? What would happen if a diver swam up into the jar? As a diver I found the answers extremely interesting. First off since every 33 feet of sea water is equal to one atmosphere of pressure the water in this giant jar would only raise up 33 feet. It would rise no further, no matter how high the tube was raised. Pressure in the tube would of course decrease as the diver ascended. The empty headspace at the top of the column is really water vapor. Pressure at the bottom of the tube (sea level) would be 1.0 ata or atomsphere. Swimming up to a mere 16.5 feet the absolute pressure would fall to half or .5 ata and would be equal to an altitude of 18000 feet! At 24 feet pressure would be equal to .3 ata or 30000 feet. Almost the pressure equivalent of an astronaut's space suit! Mt Everest is 29000 feet. Two problems will occur. First, a diver breathing air at 24 feet in the water column will become unconscious from insufficient oxygen (hypoxia), because the oxygen partial pressure at 30000 feet of altitude is only .06 atm or equivalent to 6 percent at sea level. The astronaut's suit is filled with pure oxygen. Second, just as decompression sickness (DCS) will occur from poor diving practice, acending to quickly, etc, the diver will develop incapacitating or fatal altitude DCS as the nitrogen (which makes up most of our air, as you may know (all you divers should!)) dissolved in our tissues becomes bubbles. Think about this!! This blows my mind! As diver we follow the Recreational Dive Planner (RDP) or our dive computer to stay at certain depths for specific amounts of time so we don't absorb to much and/or we off gas the nitrogen as we slowly ascend and do our safety stops. It never occured to me that we already have nitrogen dissolved in our tissues just standing, walking around at sea level. Nor the fact that astronauts have to off gas nitrogen before they decompress into their space suit pressure. They breathe pure oxygen for up to four hours at sea level. Think about this artifical world: A column of compressible air more than 100,000 feet tall was replaced with a 33 - foot tall column of incompressible sea water.

The article goes on into some other interesting points such as cold boiling. Kudos to DAN and the aurthor Dr. Richard Vann.