Dive Training Blogs

Oxygen Toxicity

Published

6 years ago

January 24, 2019

By: Gemma Smith

The existence, development, and continuing survival of human life is nothing short of incredible. This is especially true when we consider how many different factors had to come together to make life here on earth possible. There is no more obvious example of this ideal melding of variables than in the air around us. We all remember our basic science from school. Here we learnt the air around us is about 21% oxygen and 79% nitrogen (give or take the odd trace gasses). As far as our human body is concerned, we can take or leave the gas nitrogen. On the other hand, oxygen is absolutely critical to our survival.

Without this tasteless, odourless, colourless gas, we simply wouldn’t be here. We all know that too little oxygen (hypoxia) is a BAD thing. Less commonly known is the fact that too much oxygen (hyperoxia) is equally bad. Yes, in excess, oxygen is, in fact, toxic to us. Now, this wouldn’t be so much of an issue if we kept our feet firmly on terra firma…but we are divers. We journey into a new dimension, with new rules, and therefore new risks.

Partial Pressure

In your initial scuba diving class, you will have learnt about Dalton’s Law. This Law states that the total pressure exerted by a gas mixture is equal to the sum of the partial pressures of the different gases in the mix. So, at the surface, the partial pressure of oxygen is 0.21 (21% oxygen breathed at 1-atmosphere pressure). This changes when we dive. The increasing depth when we submerge causes an increase in the pressure around us. This means an increase in partial pressure as well. The partial pressure of the oxygen in our breathing gas will of course rise. This can potentially cause all kinds of issues.

These issues are especially pertinent for divers today. There has been an increase in the use of Enriched Air Nitrox (a gas mixture with a higher than 21% oxygen content). Deep diving beyond recreational limits (most often set at depth of 40m/130ft) is now commonplace. This type of diving requires the carrying of various gas mixtures. Some of these gasses will have a higher than normal oxygen content in certain designated cylinders. This is to aid and accelerate any decompression that may be incurred while at depth. Finally, the growing use and popularity of Closed Circuit Rebreathers also has implications. Many of these units utilise pure oxygen as one of the onboard gasses. This means that more than ever we need to be aware of our oxygen levels. Alongside the dangers of insufficient oxygen, it is equally important that we can spot potentially fatal problems that can occur because of too MUCH oxygen.

Types of Oxygen Toxicity

Very broadly speaking, oxygen toxicity splits into two main types. These are Central Nervous System Oxygen Toxicity (CNS), and Pulmonary Oxygen Toxicity. In all but the most extreme dives, the most common issue for divers will stem from CNS toxicity. This usually happens by breathing a gas mixture at the wrong depth. The partial pressure of oxygen (PO2) in the mix should never exceed 1.6 ATA (Atmospheres Absolute). To put this in context, breathing pure oxygen should not happen deeper than 6m/20 ft to ensure the PO2 does not exceed 1.6. Ideally, unless decompression is happening, your PO2 should be at no higher than 1.4. Pulmonary Toxicity, on the other hand, comes from breathing an elevated partial pressure of oxygen over an extended period of time. Oxygen toxicity is a fascinating and important subject. It is worth noting though that it is still not fully understood on all levels. Prevention, as in most things, is better than cure.

Let’s look a bit closer at the signs and symptoms of each of the main types of oxygen toxicity:

Central Nervous System Toxicity

The chance of problems with CNS toxicity is most likely in the kind of diving many sport divers do. These dives are typically short durations at depth, but potentially much higher than normal PO2 exposures. As we have already said, CNS toxicity tends to happen when breathing a gas mix that exceeds a PO2 of 1.6. Dipping below the maximum operating depth for what you are breathing, or breathing the wrong gas, are easy ways to exceed your PO2 limits. To help you remember the key things to look for both in yourself and others, remember the acronym CON-VENTID.

CON – Convulsions. These convulsions in and of themselves are not lethal. Convulsions underwater increase the likelihood of you losing your regulator. This can be fatal.
V – Visual disturbances. This can range from tunnel vision to blurring.
E – Ears. A ringing in the ears or other auditory disturbances.
N – Nausea. Intermittent or constant, with varying severity.
T – Twitching. Most commonly noted in the facial muscles, although not always easy to see when wearing a hood and mask.
I – Irritability. Any kind of character change.
D – Dizziness. Feeling confused, or a sense of vertigo.

Of course, the first thing to point out is that many of these signs and symptoms overlap with other common diving problems. Nitrogen Narcosis can produce many of the same effects.

Knowing all the possible signs and symptoms to look out for is nonetheless important. It is worth noting though that for many CNS toxicity cases there may be no warning. Convulsions will be the initial, and clearly blatant, indication that something is seriously wrong.

Pulmonary Oxygen Toxicity

Pulmonary toxicity tends to occur in only the most serious of technical dives. Extreme depth or duration can mean breathing an elevated PO2 for many hours. The partial pressure is usually not high enough to cause immediate CNS issues. However, over a significant time period irritation of the lungs may occur. This can cause a burning sensation in the throat, coughing, difficulty breathing or shortness of breath, among other things. Published tables show the maximum amount of time considered safe to stay at a certain PO2. Technical divers planning to do excessive decompression are well advised to implement air breaks. This allows the lungs to have a break from a high PO2 for a period of time. It is also important to consider that Pulmonary oxygen levels do not decrease with a surface interval. This means even recreational divers can be at risk of pulmonary problems when completing multiple dives with nitrox over multiple days.

Preventing Oxygen Toxicity

As with everything related to the human body, nothing is set in stone. Day to day variables will cause your body to react differently to situations. All the limits set in place for avoiding oxygen toxicity are guidelines. It is always prudent to work well within those limits. There is no way to guarantee that oxygen toxicity will not affect you. There are however several steps you can take to minimise your risks:

Analyse your gas – Never breath anything that you have not personally analysed. Calibrate the analyser, analyse your gas, and then correctly mark that cylinder. This includes writing what percent you analysed, and what the maximum operating depth for that gas is. All divers, without question, must do this for every single cylinder that they take in the water.
Watch your depth – Even when a diver correctly marks all gasses, if they do not stick to depth limits they are not helping themselves. Most dive computers now have alarms for when you exceed the depth of the gas you have programmed in. Dive computers are also a good way of tracking your oxygen exposure over several dive days. Stay aware, and make sure you maintain good buoyancy control at all times.
Avoid strenuous activity – Carbon dioxide has been shown to increase the likelihood of oxygen toxicity. Never work hard underwater, or get out of breath. Make sure your regulator is properly serviced to ensure an easy breathe. If you do have to work physically underwater it is worth considering the option of a full face mask. There are many options we as divers can take to limit our risks. It is important that we utilise all that is on offer to keep us safe.

Both types of oxygen toxicity are something all divers need to be aware of. Whether doing shallow or deep dives, recreational or technical, it is important to always know and be aware of what you are breathing, and what depth you are at. It may save your life.

To find out more about International Training, visit www.tdisdi.com.

Up Next

Dive Myanmar with the Phinisi

Don't Miss

Deptherapy shortlisted for 2019 Soldiering On Award

International Training

From its humble beginning in 1994 to today, the group of training agencies Scuba Diving International (SDI), Technical Diving International (TDI), and Emergency Response Diving International (ERDI) form one of the largest diving certification agencies in the World – International Training. With 24 Regional Offices servicing more than 100 countries, the company today far exceeds the original vision the founders had when they conceived the idea on a napkin, sitting at a kitchen table in the early 1990’s.

Blogs

Jeff Goodman Launches Underwater Moviemaker Course with NovoScuba

Published

1 week ago

December 9, 2024

Team Scubaverse

Transform Your Dive Experiences into Cinematic Masterpieces

NovoScuba has partnered with acclaimed underwater filmmaker Jeff Goodman to introduce the Underwater Moviemaker Course—a revolutionary program designed to equip divers with the skills to capture the breathtaking beauty of the underwater world.

Whether you’re an aspiring filmmaker, an avid diver, or a photography enthusiast, this course offers the tools and expertise needed to create stunning underwater videos. From vibrant coral reefs to curious marine life, you’ll learn how to film, edit, and produce captivating underwater stories, all with expert guidance from a seasoned professional.

Jeff Goodman: A Legacy in Underwater Filmmaking

Jeff Goodman brings over 40 years of experience in underwater film production for television to this course. Reflecting on his career, Jeff said:

“Although technology has dramatically changed, the basics of underwater filming remain constant. This course covers crucial skills for producing great videos. Whether you’re creating professional broadcast films or high-quality hobby videos, the fundamental principles are the same.

A camera operator must master their equipment to capture those magical underwater moments effortlessly. But beyond technical know-how, underwater filmmaking is about having fun and enhancing your diving experiences. So, take your time, learn at your own pace, and enjoy this creative journey.”

About NovoScuba

Founded in 2023, NovoScuba is reshaping dive education with a comprehensive, digitally native platform. Offering cutting-edge training programs for divers at all levels, NovoScuba sets a new benchmark in the diving industry by combining innovation with accessibility.

With ISO-certified courses, a student subscription model, and multilingual support, NovoScuba ensures that dive education is inclusive and engaging. More than just a training provider, NovoScuba fosters a global community of divers committed to exploration, collaboration, and sustainability.

Join the NovoScuba Underwater Moviemaker Course Today!

Dive into the world of underwater filmmaking and start creating cinematic stories that inspire. Learn more about the course and enroll today at www.novoscuba.com/novoscuba-underwater-moviemaker-course.

EXCLUSIVE: Jeff Goodman interviews Mark Spiers, CEO of New Scuba Diving Training Agency NovoScuba

NovoScuba’s Game-Changing Approach for Dive Store Owners: WE PAY YOU!

The diving world thrives on passion and adventure, but for many dive store owners, the financial and operational challenges can be as deep as the ocean.

NovoScuba, an emerging force in the diving world, is on a mission to transform this landscape for the better. With a revolutionary approach to dive store and training agency partnerships, NovoScuba is setting new standards for how dive stores can thrive while keeping their focus on delivering exceptional diving experiences.

underwater videography course

A New Paradigm: NovoScuba’s Bold Mission

NovoScuba’s mission is straightforward yet profound: to disrupt the traditional dynamics between dive store owners and training agencies. Traditionally, dive stores have been subjected to substantial fees charged by training agencies, for membership, materials and certifications. These costs have often placed a heavy financial burden on store owners, cutting into their profits and limiting their ability to offer competitive prices to customers.

NovoScuba flips the script by offering a model where dive stores earn money, instead of paying high fees. Dive stores receive commissions for every student they register, and their certification costs are covered. This new model not only boosts profitability but also ensures clients get top-quality training at unbeatable prices.

Financial Upsides: Earn From Student Registration

NovoScuba’s approach is simple yet revolutionary. Dive stores partnering with NovoScuba can earn commissions for every student they enroll.

Here’s how it works: For every student enrolled through NovoScuba, dive stores receive a commission. Each student enrolled will receive their e-learning materials and certification credit included in their subscription. This arrangement is a significant departure from the traditional model, where dive stores often struggle to manage high overhead costs related to training fees and certification expenses.

underwater videography course

NovoScuba’s approach ensures that dive stores can focus on what they do best—providing top-notch diving experiences—without being bogged down by excessive financial burdens, and the need to carry large stocks of materials.

Quality Training at a Great Price

NovoScuba stands out by offering high-quality, ISO certified, training that doesn’t break the bank, in fact our students will pay less than with most competing agencies. Clients benefit from top-notch education and safety standards at competitive prices. Dive store owners can confidently promote NovoScuba’s programs, knowing they’re offering fantastic training at affordable rates. This balance of quality and affordability helps dive stores build a strong reputation and attract more customers.

Your Brand is Your Business: NovoScuba’s Commitment to Showcasing Your Identity

At NovoScuba, we understand that your brand is your most valuable asset, and we’re committed to putting it front and centre. Unlike agencies that charge high fees to promote their own brand, we believe in investing in yours. With NovoScuba, you won’t be paying to advertise someone else’s logo alone, — our focus is on showcasing your unique identity. Certifications prominently feature your brand, as well as the training agency, reinforcing your store’s image and brand every step of the way. We’re here to support and elevate your brand, ensuring that your investment directly benefits your business.

Affordable Membership: An Investment in Your Success

NovoScuba’s membership model is designed with dive store owners in mind. Membership fees are kept low and include annual Pro member fees for your team. Payment can be made monthly or annually in your local currency, avoiding the hassle of exchange rate fluctuations. NovoScuba promises no exchange rate changes without a six-month notice, ensuring financial stability and simplifying budgeting. With a membership lasting 12 months from date of joining, you’ll enjoy a full year of NovoScuba’s benefits and support.

underwater videography course

Streamlined Operations: Simplifying Your Workload

Handling administrative tasks can be a challenge, but NovoScuba makes it easier. We’ve streamlined certification procedures and reduced paperwork to help dive stores operate more efficiently. Certification processing is quick and straightforward, allowing more focus on teaching and customer service. Our system minimises bureaucracy by storing necessary forms in student profiles, reducing paperwork and administrative delays.

Crossover Made Easy

For dive stores looking to transition to NovoScuba’s model, the crossover process is designed to be smooth and hassle-free. NovoScuba provides support to ensure that the transition is as seamless as possible, helping dive store owners integrate into the new system with minimal disruption. Experienced dive Pros don’t need to undergo extensive retraining. Our crossover is designed to familiarise Pros with NovoScuba’s user-friendly platform, standards and course structures, and not to waste time and expense re-training in water.

With just a few simple steps, you’ll be ready to offer top-notch training through NovoScuba.

Comprehensive Business Support and Training Included in Your Membership

NovoScuba goes beyond financial benefits by offering experienced support and training. This value added service includes:

Business Training: Optimise your operations with guidance on marketing, customer service, and best practices.
Marketing and Promotion: Access resources to attract new customers and boost your store’s visibility. Enjoy cross promotions with NovoScuba to gain increased exposure.
Ongoing Support: NovoScuba’s commitment to its partners extends beyond initial training and setup. The company offers ongoing support to address any issues or questions that arise. This continuous support ensures that dive store owners have a reliable resource to turn to whenever they need assistance.

underwater videography course

Embracing Digital Natives: Instant Evolution and Continuous Improvement

NovoScuba’s digital-native approach is a game-changer. Leveraging cutting-edge technology, we ensure our services evolve and improve swiftly. Dive stores benefit from instant updates, the latest features, enhancements, and effective solutions, keeping them ahead of the curve. This continuous improvement helps dive stores stay competitive and deliver exceptional services. Whether it’s a new course update, additional marketing resources, or improved e-learning functions, NovoScuba’s digital infrastructure ensures that dive stores are always equipped with the most current and effective solutions. This continuous evolution not only helps dive stores stay ahead in a competitive market but also ensures they consistently provide top-quality services to their clients.

Why Is NovoScuba Doing This? – Fair Profit Sharing for Greater Access and Growth

At NovoScuba, we’ve taken a bold step by paying commissions to stores rather than following the traditional model of training agencies charging high fees. Our mission is to make diving accessible to everyone and to foster a growing community of new divers and continued education. By redistributing profits more equitably between stores and training agencies, we aim to create a more supportive and collaborative environment within the industry. We believe this approach not only helps individual stores thrive but also stimulates overall growth and innovation in diving. Our commitment to fair profit sharing reflects our dedication to the long-term health and expansion of the diving community.

Everyone is getting a piece of the pie.

Getting Started: Join the NovoScuba Revolution

Ready to revolutionise your dive store experience? NovoScuba is here to support your journey toward reduced costs, increased profitability, and enhanced operational efficiency. Get in touch with our team to learn how NovoScuba can transform your business.

For more information, email info@novoscuba.com or visit www.novoscuba.academy.