The Combined Effects of Increased Levels of Carbon Dioxide and Breathing Resistance Caused by Underwater Breathing Apparatuses

Excellent Read!

The Dive Lab

ONR_Book1 (2)Between July 15-17, the Office of Naval Research (ONR) and the Naval Sea Systems Command (NAVSEA) hosted an undersea medicine progress review meeting in Durham, North Carolina. The presentations focused primarily on topics of interest for the Navy, but most of the research also benefits recreational and technical divers. One topic I found particularly interesting concerns the combined effect of increased carbon dioxide levels (CO2) in breathing gas and the breathing resistance that breathing apparatuses impose on divers.

If breathing is unimpeded, slightly increased levels of CO2 pose no problem. However, the more CO2 that is inhaled, the less CO2 can be added, and a larger breathing volume per unit of time will be required to wash out the same amount of CO2. This increase of breathing volumes occurs automatically, successfully washing out the metabolic CO2 and maintaining a nearly normal level…

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How to Calculate a Scuba Weight Belt

Reprinted from eHow

Diver wearing hard weight belt.

Diver wearing hard weight belt.

The amount of weight required to safely descend at the start of a dive and to maintain a safety stop at the end of a dive is not limited to what is installed on a weight belt. Proper weighting depends on many variables such as exposure suit type and thickness, tank composition and diver experience, in addition to body weight. For a streamlined profile, weight can and should be distributed so the diver can establish an efficient position in the water. Distributing weight among the weight belt, BCD, ankles and/or tank can offset pressure in one area, thereby increasing comfort.


Calculate Diving Weight
Multiply your weight by 10 percent to calculate the amount of weight to carry when you’re diving in salt water wearing a 3mm wet suit with an aluminum tank (80 cubic feet). For example: 150 pounds x 0.10 = 15 pounds
Add one pound for each additional millimeter (mm) of thickness if your wet suit is thicker than 3mm. For example: 7mm wet suit is 4mm thicker than 3mm, so four pounds is added to the calculation in step one.
15 pounds + 4 pounds = 19 pounds
Subtract four pounds if you’re diving in fresh water, such as in a lake. For example:
Freshwater wearing 3mm wet suit (150 pounds): 15 pounds – 4 pounds = 11 pounds
Freshwater wearing 7mm wet suit (160 pounds): 19 pounds – 4 pounds = 15 pounds
Round up (i.e., add a pound or a few) so that you can evenly distribute weight or if your fat-to-muscle ratio is greater.
Evenly distribute the weights in your weight belt pouches so that the right and left sides carry equal weight. Consider distributing weight around your body to reduce the amount of weight on your hips.
For example, wear a pair of two-pound ankle weights to reduce the weight belt load by four pounds; weight can also be installed in your BCD weight pouches or pockets.
Don the weight belt and check that the weight distribution and length are comfortable. Adjust the weights and the belt length accordingly if desired.

Weight Check
Check that you are properly weighted before your dive by donning your scuba gear with a near-empty tank (80 cubic feet aluminum tank containing 500 psi).
Enter the water and float on the surface of the water. Place your regulator in your mouth and hold still (i.e., no kicking, sculling or moving).
Hold your low-inflator hose and raise it high vertically. Press the deflate button to completely deflate your BCD while inhaling deeply and holding your breath.
Check that you are sinking momentarily. If you end up floating at eye level, your weight is fine; if you are floating higher, add two to four pounds of weight; if you descend so that the water surface is above your head, remove at least two pounds of weight.

Thanks eHow

Kathy Dowsett

Review :: ScubaMax Integra 2 BCD

ScubaMax Intrega II available @ kirkscubagear

ScubaMax Intrega 2 available @ kirkscubagear

As an avid diver I was excited to get my kids involved in the sport, but really did not want to have to shell out a small fortune for gear, and of course I wanted to make sure that the gear was reliable.

I scuba dive, love the sport with a Zeagle Ranger BCD, but was not too sure how long my kids would stay committed, so I really could not see spending too much for BCD’s for them. I did not want to buy used equipment for safety concerns. I was at an impasse of sorts then I found the ScubaMax Integra 2 BCD’s at kirkscubagear.

I purchased 2 size mediums for my kids, and honestly wish I would have purchased a 3rd for myself. The suits are well made, with lots of D-rings so that you can hang stuff from the BCD, and has nice big pockets which are great for holding your dive accessories. The plastic tank mount is also integrated into the suit.

They fit is spot on and the kids love them.

These suits are an excellent option. If you are considering renting used or even purchasing used you should consider these BCD’s before you make your choice. As an avid diver, safety is always in the forefront of my thinking especially when it comes to my kids so having the peace of mind that they are safe in great equipment really has given me peace of mind when I take them out. The ScubaMax Integra II is a great product from ScubaMax. I can not say enough positive things about these BCD’s. I really did not expect to be find quality gear in my price range. This is quality affordable scuba gear!

I would honestly say this is one of the best purchases I made in a long time. Delivery took about 2 weeks from the time I ordered and that worked out perfectly. Overall this has been a great experience and I hope my kids take to the sport and continue to show enthusiasm.

In the future I plan on getting all my scuba gear from kirkscubagear, because the price is right and the quality is exactly what I want!

Thanks to George W. for his review of the ScubaMax Integra 2. This is a honest review, from a kirkscubagear customer.

Kathy Dowsett

ScubaLab: 5 Tips for Buying the Perfect Dive Mask

Reprinted from ScubaLab

dive masks---all makes and models available @ kirkscubagear

dive masks—all makes and models available @ kirkscubagear

Optimizing your field of view, both horizontally and vertically, is the primary goal of a good mask. But having a good downward view is of particular importance. After all, downward is where you’ll find your gauges, buckles, D-rings, BC pockets, weight ditch handles and just about everything else you’re going to want to grab. The better your downward view, the easier it is to see and to access your gear.

It may not seem like a crucial piece of life-support gear for scuba diving, but your dive mask is important. Need help finding a well-made mask that’s perfect for you? ScubaLab explains five features you should understand when shopping for your next window on the underwater world.

Low Volume

Low volume masks are nice because they require less breath to clear. They also create less drag when cruising through the water column, and they tend to provide a wider field of view because the front lenses sit closer to your eyes.

Read more::::::

Kathy Dowsett

History of Kirby Morgan Dive Helmets

Info about Kirby Morgan.

Kirby Morgan Dive Helmet 1974

Kirby Morgan Dive Helmet 1974

40 Year Anniversary Bucket Hat, 1974–2014. This helmet was designed by Bob Kirby and Bev Morgan as a joke, but several important findings were made as a result of water testing this unit. The helmet dives quite well and is surprisingly comfortable.

More info

Kathy Dowsett

Scuba-Fix–scuba solutions made easy

Scuba-Fix–scuba solutions made easy—-repair, not replace!

Scuba-Fix--scuba solutions made easy::now @ kirkscubagear

Scuba-Fix–scuba solutions made easy::now @ kirkscubagear

NEW to kirkscubagear! Read about this new product

BCD Valve repair kit::::::

Do you have any BCDs with broken inflator or dump valves that needs to be fixed?
You find it such a waste to throw away a otherwise perfectly looking BCD and hope the valve can be repaired or replaced?

Dive shops tells you that the valve cannot be repaired or even if repaired, it would not last?

Scuba-Fix may have the solution for you. For years, nobody really found an efficient way to service or repair broken BCD valves. Most BCD/s were either thrown away or write off when the valve parent material gives way. These BCD/s are often in full working condition other than that broken valve. These BCD/s, are wasted!

We have develop the world’s first DIY BCD Repair Kit such that you can carry out the repairs on your own with guidance from our instructional video. And if u are still not confident with doing it yourself after watching the video, you can send your BCD to us for repair at a nominal fee (my supplier)

As of now, we have repair kits for SeaQuest, US Diver, Aqualungs, Mares, Aeris, OMS, Halcyon, Dive Rite, Frog, Oceanic, Beuchat (47mm & 51mm), Genesis, Sherwood, Zeagle, Aquatec, Seac-sub, Cressi Sub, Scuba-Pro.

If your BCD belongs to a brand that is not listed above, do drop me an email :

Included in package :
1 x BCD – Valve port
1 x glue tube
1 x sandpaper
1 x Instructional Video

WATCH the Video:::

Forum on ScubaBoard on Scuba-Fix:::


The Repair Process

1. Are there any other tools needed for the repair?
Ans : Yes, you will need some household items like a pair of cutters, a piece of cloth and turpentine.

2. I have a BCD that you do not have a repair kit for. Will you be developing other brands soon?
Ans : We have another 5 brands lined up. Some are already manufactured and currently undergoing quality testing. Do email us your enquiry and we will advice accordingly.

3. I have a BCD that you do not have a repair kit for. Can your repair kit be use to repair my BCD?
Ans : Yes it can be done. However, you may need to enlarge the current hole on the BCD and on top of that, you will need to purchase an inflator hose either from SeaQuest, US Diver, Mares or Oceanic ( according to the repair kit you use) in order to use your BCD. In short, mix and match. We have already done numerous of these cross over repairs especially for resorts and dive centers that have lots of spare inflator hoses from other brands.

4. I’m not confident of carrying out the repair by myself after watching the video provided. Is there an authorize workshop to carry out the repair for me?
Ans : Although we have tested this repair on a non-diver with non-technical background and he managed to easily replace and repair the BCD, we understand these things happen. There are a few things you can do 1) You can bring your BCD to a dive shop repair center and see if they can help you out with a small cost?

5. I ran out of glue during the repair, where can I get the adhesive?
Ans : Under accessories, u can order additional adhesive if you require. Rests assure that the amount of adhesive we provide is more than sufficient for the repair work.

6. Do you provide warranty for the repair kit?
Ans : Yes, warranty for the product is two years, please refer to our terms and conditions of sales. Two years is a conservative figure, we actually expect our product to last four to five years. The moment you receive the repair kit, you will be able to tell that our valve material and quality will out last any current original valves in the market.

7. I’m an owner of a dive shop and I would like to organize a group purchase, would you be able to give a live demonstration of the repair process?
Ans : Yes, if you are located in South East Asia or bypassing Singapore reroute to diving in Asia, Scuba-Fix can organize a time and place to provide the demonstrations, give guidance and ensure all repair jobs are carried out properly. It is a good idea as we will be available to monitor all repairs, have spare repair kits on standby and quite possibly give you a group discount too. Drop us an email to discuss further.

Shipping and Delivery

1. What is your refund policy?
Ans : If you don’t like what you see when you receive our products, you can get a full refund from us by shipping the product back to us within 30 days. We will refund you the full amount less the delivery charges. Please read Terms and Conditions Of Shipping for more details. Note: this does not apply to the ‘SAYNOSHARKFIN’ TABLE CARDS. As part of the sales will goes towards Sharksavers . There are no refund for cards purchased.

2. Will you delivery overseas?
Ans : Yes, we deliver WORLDWIDE. Any questions about the repair work after watching the repair video please send us an email or call us anytime and we will answer any queries right away.

3. You are using SingPost to deliver my purchase. Are there other methods of delivery provided by you?
Ans : Yes, Shipment is available via FedEx. (additional charge/faster arrival time) Please email for rates.

Kathy Dowsett

Just because you want to know @ kirkscubagear

St Thomas 1Kirkscubagear is online, e-commerce business that I operate from my home at 113 Cottonwood Crescent, London, Ontario, Canada N6G 2Y7. (as listed in Google) It is not a storefront nor does it have stock/inventory.

Kirkscubagear does not offer scuba lessons. It is strictly an alternative shopping site for divers who wish to purchase quality scuba/snorkeling/electronics/outdoor gear products at reasonable prices. All products are backed with a manufacturer’s warranty from my suppliers. Kirkscubagear is not a “grey market” business. Referrals from kirkscubagear for lessons, tank fills, and store gear are made at the customer’s request to a local business in London, Ontario, which is supported by me.

Most divers know that scuba gear is not made in Canada, except for Bare, which is located in Quebec, Canada. Most of my products ship to Canada from the United States/China from an assortment of suppliers that work with me.

I am pleased to offer products from Canada such as Carry Yak, Chawel, Paddle Wrap, Ice Halo, Chilly Dogs, Canned Oxygen + and Sportstalgid Bracelets. These products ship within Canada.

Shipping is always an issue with customers. All of my products ship via USPS (air mail) to eliminate extra costs. USPS charges are based on weight and the size of the box. Scuba Tanks are shipped via UPS, because of their weight.

Kirkscubagear does not charge customers more than my supplier charges me for shipping your purchase. I do not believe in making a profit from shipping charges.

Have a friend in the United States, or an address, or taking a vacation in the U.S., or have a UPS box? I am happy to ship your purchase there, as many products over $50 ship for free within the U.S., but unfortunately not in Canada.

I appreciate the support of Canadians who purchase from my site.

Questions, concerns, inquiries are always welcome. Email, or call 519-641-4948. Your inquiry will be answered in a timely matter.

Kirkscubagear is growing to provide Canadian divers/snorkelers with quality gear that doesn’t break your bank account. Kirkscubagear is an ocean conservationist, believing in the preservation of our coral reefs and the life underwater. We also support SOS (Save our Wrecks, Ontario) diving for the disabled, swimming for the disabled, Save Our Sharks and Save our Sea Turtles.

Kirkscubagear is a social butterfly.





Scuba Deals for Canadians

Ontario Divers

Kathy Dowsett, owner and operator and a PADI certified diver
113 Cottonwood Crescent London, Ontario N6G 2Y7 :::: 519-641-4948 or 519-520-7480 after 5 pm., please. (Canada only)

Shopping For Snorkeling Gear: What You Need To Know

Cressi Snorkel Set @ kirkscubagear::$49.95

Cressi Snorkel Set @ kirkscubagear::$49.95

If you are planning on taking up snorkeling as a hobby in the near future, you will need to get yourself kitted out in the latest gear. So, prior to heading to the beach for an action packed weekend of exciting snorkeling action, make sure that you head off to the local snorkeling apparel and equipment store. You may not be fully up to speed on what kind of accessories there are available, so, in this article, we will take a look at some of the essential apparatus that you will need in order to make the most of this exciting and unique pastime, as well as making it more comfortable and fun.

The Essential Items

The snorkel is obviously the most important part of a, scuba divers equipment, and it is where the term ‘snorkeling’ comes from. When the time comes to choose a snorkel tube, you will find that there are two main types to choose from. The J-shaped tube or the flexible tube. As a rule, it is much better to buy a flexible tube rather than a J-shaped tube, as they are easier to use, and although they might cost a bit more, the extra expense is well worth it. Next, comes the mouthpiece, and again there are two main types to choose from, either rubber or silicon. Even though rubber mouthpieces are very proficient, they can add extra pressure onto the jaw line, and they can be uncomfortable to use for lengthier dives, therefore, it is worth investing in a silicon mouthpiece. Also, it is worth investing in a good pair of flippers, which will help to propel you through the water, and again there are a lot to choose from, however, it is worth taking the time to find a pair that are comfortable to wear, even if they cost a little bit more.


Once you have kitted yourself out with the basics, you can move on to buying some accessories, which will hopefully improve your snorkeling experience. There are many different accessories to choose from, however, some are a lot more useful than others. One thing you can do to make your snorkeling trips much more comfortable, is to upgrade your snorkel tube to one that has a purge valve fitted. Without a purge valve, any water that enters the tube will have to be expelled by you, through blowing hard through the tube. With a purge valve fitted, a simple maneuver of the valve will expel the water with minimum effort required on your part.

You can save on snorkel gear by purchasing it online as you will be able to do some product comparisons to find the best deal. This allows you to make the most of the money you have to spend.

Kathy Dowsett

Is a knife part of your dive kit?

Check out this article I found on the Under Pressure Dive Blog!
© 2014 Stephen Krausse. All rights reserved. Used with permission.

Tusa X-Pert II Point @ kirkscubagear

Tusa X-Pert II Point @ kirkscubagear

If you’ve been diving a while you may already have a strong opinion about whether or not you need a dive knife and; if you own one, which type you prefer. If you’re a new diver you may be wondering “Do I need a dive knife?”

Like many ‘seasoned’ divers Lloyd Bridges set the bar for me when it came to dive knives as ‘Mike Nelson’ in the Sea Hunt series. Nelson’s character sported what basically amounted to a short sword. So, when I was looking at display of dive knives I knew exactly what I wanted and bigger was better.

When I purchased my first SCUBA rig I was so excited about SCUBA diving! I wanted everything. No, scratch that I wanted EVERYTHING! I wanted to be the most prepared diver with the latest tech. As part of that kit I purchased a dive knife. Not a modest 2.5 inch BCD pocket type knife… no sir not me. This was the full on 5″ inch titanium blade with the super duper ankle holster (although I haven’t tested it, I think it might glow when orcs are about).

Getting to the Point
So, what is the ‘point’ of the dive knife or ‘diver’s tool’ as some agencies have taken to referring to it?

“To protect myself against predators!” – uh… no. It might work on TV and movies but in real life environmental awareness, understanding & respect for the environment and maintaining your composure are far better ways to avoid a negative interaction with a predator.
”I’m a spy.” – I’m going to have to give you that one. If you’re the likes of James Bond you may need one.
“I wanted to get a souvenir.” – big NO – please leave the reef in the condition you found it for the rest of us – don’t be THAT guy (or gal).
“I’m hunting abalone.” – fair enough, there are some foods that you can harvest with a blade.
“To escape entanglement.” – Yes! READ MORE

Kathy Dowsett

Under Pressure Dive Blog

First impressions: The DiverGuard

As scuba diving gains popularity, many new products seek to mitigate the inherent risks of the sport. The most important precautions should always be adequate, quality training and sound judgment, but in addition to the basics, many divers already carry items designed to increase their safety both underwater and at the surface, including whistles, DSMBs and strobes — as they should. And more options are added every season. In this blog post, I’ll look at one of the newest, the DiverGuard.

DiverGuard--available @ kirkscubagear

DiverGuard–available @ kirkscubagear

Shallow water death syndrome

Every year there are a number of dive deaths for which there are no real explanations. Many of these deaths occur in fairly shallow water; the divers are experienced, and there seems to have been no panic, outside influences or equipment failures. The divers simply drowned. Typically, these deaths are explained as sudden illnesses or seizures, which paramedics would have treated had they occurred on land. But because the victim is stricken underwater, he drowns before help can arrive. The victim’s buddy should help get the diver to the surface and start first aid, but statistics show that this doesn’t always happen.

Enter the DiverGuard

A new product, called the DiverGuard, seeks to remedy this. This small unit attaches to the low-pressure inflator, substituting for the current inflation and deflation unit. It electronically monitors the diver’s breathing, starting at around 10 feet, and stops again when the diver reaches 3 feet of water. If, at any point in between those depths, the diver stops breathing for 40 seconds or more, an audible and visible alarm sounds and flashes, alerting the diver’s buddy and other divers in the area. The diver, or another diver, has 7 seconds to press a reset button before the DiverGuard starts inflating the BCD, sending the diver to the surface. The alarm continues at the surface, helping divers and surface crew locate the diver in distress. Read more::::

Kathy Dowsett