What You Need to Know About Currents
The thrill of flying over a reef, pushed onward by a strong current, can be one of the most exhilarating experiences in diving. But diving in currents can lead to problem situations if you’re not vigilant.
A number of factors cause currents, including the tides, wind, and thermally unstable water columns. Usually currents run horizontally, parallel to the earth’s surface — these are perfect for drift dives. Certain situations, however, cause currents to run vertically up (up currents) or down (down currents), while other currents can create a horizontal vortex. If a diver gets caught in one of these currents it can quickly lead to a dangerous situation. Down Currents
A down current occurs when a current hits the face of a wall or when it runs at a right angle to a drop off. Down currents are also possible when two currents moving in opposite directions meet or move over each other. These types of currents have a nasty reputation among divers, and for good reason: they can quickly drag you far deeper than your planned depth. Sometimes this occurs gradually, and you won’t realize it until you feel the need to equalize, or until you look at your depth gauge or dive computer. But in some situations, a down current can pull you from 15 feet to 65 in a few seconds.
Most down currents lose strength the deeper they go, but don’t just wait for the ride to end, though, as there’s no telling how deep the current will take you. If you get caught in a down current, try to remain calm. Stop. Think. And then act. Maintain natural breathing to conserve air, and swim out into the blue. Although you may be in a scary situation, remember that down currents generally become weaker further away from the wall or drop off. While you’re swimming out, you also want to swim up — aim to swim a 45-degree angle.
If the current is especially strong you may want to inflate your BCD, but remember, an inflated BCD creates a larger surface area for the current to push against, so it might not help as much as you think. If you do inflate your BCD, prepare to deflate it rapidly once you’re out of the current to avoid a run-away ascent. Avoid dropping your weights unless you absolutely must.
Another option is to get as close to the wall as you can and climb up. The current is likely to be strongest here, and you might need to hold on to the coral to pull yourself up. If you must use this option, do so with caution and try to keep yourself and the coral as safe as possible. Try to hold on to dead coral and avoid stinging hydroids. Up Current
As with down currents, up currents can occur when a current hits the face of a wall. These are dangerous because they can pull you up to the surface very quickly, which can lead to a host of problems, including decompression sickness, a lung over-expansion injury or arterial gas embolism. Try to maintain the same calm as with a down current, and react similarly by swimming away from the wall or drop off into the blue. Deflate your BCD and swim down. Washing Machine
A washing-machine current occurs when the bottom typography bounces currents around. These types of currents can push you in all directions, creating a feeling of extreme disorientation, which can be amplified when your bubbles get swirled around, making it very difficult to tell which way is up. As with up and down currents, try to swim out of the current horizontally while swimming slightly against the push of the water to avoid drastic changes in your depth. Vortex
Very little information is available about vortex currents as they only occur at a few dive sites around the world. The best way to deal with this kind of current is to avoid getting caught in it all together. If you do get caught in one, try to conserve as much energy as you can, wait until you feel it weakening slightly and swim perpendicularly out of it. This video
of Socorro shows how easily a diver can get caught in a vortex. Note the horizontal snake of bubbles that acts as an early warning that this kind of current is present. How Do You Recognize Types of Currents?
You can often predict strong currents, horizontal or vertical, by looking at the surface of the water. Areas where the surface is choppy without a moderate to strong wind, mixed with areas of very smooth water, could indicate a strong current. If the boat that you’re diving from is tied to a mooring buoy, look at the direction in which the boat is turned. If the boat is tied off at the bow, the boat will be facing into the current; if the mooring line is tight, the current is likely moderate to strong.
Underwater you can tell which way the current is running by observing the sea life around you. Soft coral sways in the direction the current is traveling, and fish face into the current, so if you see a school of fish pointing in one direction, that’s where the current is coming from. If a school of smaller fish is swimming around freely in different directions, there’s probably only a slight current, if any at all.
Bubbles can also tell you a lot about the current. Strong down currents can sweep your bubbles into the depths, as can horizontal currents. One of the only ways to identify a vortex is by its distinctive, serpent-like horizontal river of swirling bubbles.
Current diving can be exhilarating and safe if you stay vigilant and practice good judgment. Learn to recognize different types of currents, and be prepared. If you’re diving in an area known to have currents, always carry a DSMB, or safety sausage, in case you get separated from your group and must surface alone. As with any dive, if you feel uncomfortable or find the currents too challenging, better to abort your dive and move to a site with more favorable conditions.
The Benefits of Diving
By Jessica Shilling
For some it´s the adrenaline rush of the exploring the deep waters, for others it´s the beauty of the reef and the marine life that inhabits it. There are many reasons to scuba dive but most would agree that they dive for the pure enjoyment of experiencing the underwater world, so different from ours and truly amazing.
Scuba diving has it all, it’s an fantastic experience that can improve your emotional and physical health while learning new skills, making friends and expanding your environmental awareness.
Just starting out? Take a look at the following list of benefits for a little encouragement.
You don't have to be incredibly fit to scuba dive. It's a sport that's easily accessible to the average person. You do however need to be in a state of good health and free of any serious medical problems. Before diving you will be asked to answer a medical questionnaire and if your instructor has any concerns you will be referred to a doctor for a check-up.
If you dive on a regular basis your general fitness will improve. Exercising in water is an excellent way to strengthen your muscles. You spend hours in the water carrying heavy equipment while swimming against the natural resistance of the water. This may sound very tiring but it feels effortless because you are too busy enjoying yourself but in reality you are getting a fantastic work out.
Gliding underwater while watching the fish go by is incredibly relaxing. Many people find diving to be a great way to get back to nature and de-stress. With practice you will learn calming breathing techniques which will not only make the dive more enjoyable but you´ll use up less air and be able to stay underwater for longer. Once you master your buoyancy it will make your diving experiences even better, it will become even more relaxing and you will feel one with the water.
One great thing about diving is meeting fellow divers. By joining a scuba diving class or club you'll immediately come in contact with a lot of people with the same hobbies who may become life-long friends. While on a dive trip its common to make friends with fellow divers on the dive boat making your vacation even more exciting.
Diving makes you appreciate the ocean even more and will bring you in contact with people that can educate you about fragile underwater habitats and the importance of preserving them. You can even join ocean advocacy groups like the Making Waves in Colorado event and volunteer to help protect marine environments.
Join the 3rd annual Making WAVES in Boulder, Colorado on September 20th to the 22nd where you´ll have the chance to enjoy insightful presentations on ocean advocacy and more from an exciting list of attendees. This multifaceted symposium and celebration highlights ocean issues, solutions and is a change making event for engagement and national action.
How to Gear up your Scuba Kit Quickly, Easily and Efficiently?
Posted by Rutger Thole
How often have you seen someone dance around in circles trying to grip their wetsuit zipper or even spotted people walking into the water like frogs because they already have their fins on, or seen their masks fly off into the air as they tried to put it on?
All of this is a complete waste of time and an unnecessary one at that. If you know how to gear up quickly, easily and efficiently, you will have far more time to enjoy diving as well.
Organizing Your Scuba Gear
Always make sure that your scuba gear is organized. If everything is in its place, you will be able to get things on much quicker as well, as you won’t have to waste time trying to find your belongings.
Not just that, you will always be aware of the condition your gear is in, enabling you to replace it as and when necessary.
Make sure, of course, that you look after your gear, drying it off before storing it and keeping it somewhere dry and safe from the elements.
Bring a Plastic Carrier Bag
How hard is it to get your hands and feet into a wetsuit? Although once on, they are incredibly comfortable, getting the suit on can be an absolute nightmare.
Interestingly, a simple plastic bag can help you with this. It goes without saying this plastic bag should be stowed away properly so it will not end up in the water. Have you ever heard of the great pacific garbage patch?
You may be tempted to use lotions to make your skin more slippery, but this can actually be damaging to your suit whereas a plastic bag does not.
Simple put it over your hand, feet, or whatever it is that you are trying to get through and you will notice it slips on and fits like a glove straight away.
Always Help Your Fellow Divers
If you see that someone else is struggling or looks like they don’t know what to do, go help them out. Just share your knowledge, including the above two points, and you will make sure they can enjoy their time a lot better as well.
Remember that scuba diving is something that you do together, which is why it operates according to a buddy system.
You are not competing to be in the water first or to have your gear on first. If you have any knowledge you can impart on less experienced divers, then make sure you do so.
This will also show them that divers look after each other and that it is ok to ask questions.
Scuba diving is fun and should be a relaxing hobby. This means that there is no time or energy to waste by things such as struggling to get your gear on.
Diving With Less Than 20/20 Vision
By Jessica Vyvyan-Robinson
For those whose eyesight requires corrective measures, the prospect of diving — a primarily visual pastime — can be a little daunting. Proper diver safety also relies on keeping a keen eye on your buddy, your location and your gauges. But a lack of 20/20 vision is by no means a barrier to diving, as there are many options available to facilitate participation despite all manner of sight issues. Many people with mild vision impairment don’t need to take any corrective action, as objects in water are naturally magnified by 33 percent. But if corrective measures are needed, there are several methods of compensating for sight problems underwater, making for safer, more enjoyable dives.
One of the simplest ways to deal with poor eyesight is to wear contact lenses, just as you would on land. Certain precautions should be taken to minimize eye irritation and to prevent losing the contacts, but generally, diving with contacts is a safe and hassle-free solution. The Diver’s Alert Network (DAN) recommends using soft contact lenses for scuba rather than hard or gas-permeable ones, however, because increased pressure may cause hard lenses to suction to the eye, causing pain or discomfort. Hard lenses typically dry wearers’ eyes out more, too, resulting in redness and irritation upon surfacing. Most importantly, soft lenses allow the nitrogen absorbed by the eye while diving to escape; hard lenses do not. Bubbles can form between the hard lens and the eye, causing blurred vision, which effectively negates the purpose of wearing the contacts in the first place.
Wearing contact lenses underwater also means keeping the eyes closed when performing any skills that require the flooding or removal of the mask. If you are enrolling in a scuba course, be sure to tell your instructor if you wear contacts so that he or she will allow you to keep your eyes closed during skills, and to wear a mask during surface water skills or swim tests. Similarly, if you’re using vision-correcting equipment, from contacts to prescription masks, make sure to alert your buddy: if you should lose your mask underwater, they need to know that they’ll need to help you find it. In terms of comfort, even soft contact lens wearers often report some dryness as a result of diving; it’s a good idea to bring lubricating drops with you to the site for use before and after diving. Rinsing lenses in fresh saline solution between dives can also minimize irritation from residual salt water; divers should consider using disposable contacts for live-aboard trips so that they can use fresh ones each day.
There are alternatives to wearing contacts while diving for those who are squeamish about using them or simply prefer not to. Depending on the severity and type of eyesight issues, the lenses of some stock masks can be quickly and easily replaced with pre-made corrective lenses. For those with astigmatism or other, more extreme vision impairment, pre-made lenses may not work sufficiently. Custom-made prescription masks are also an option, wherein a mask is made specifically to your requirements. Those who opt for prescription masks should consider purchasing two customized masks in case of loss or damage to one of them, as it can be exceptionally hard to find a replacement in many of the world’s remote dive destinations.
The most permanent alternative is corrective eye surgery, but it is imperative to consult an ophthalmologist before your first dive, after surgery, in order to respect the healing period. If not properly observed, the effects of pressure and trapped gas on an unhealed incision could be incredibly painful.
The final option, particularly for those who require bifocals, is adhesive magnifying patches, which are applied to a stock mask lens and can be purchased at most large dive equipment stores or an optician’s office.
For most people, however, contact lenses are the simplest choice for correcting eyesight while diving. They are cost-effective, and divers are able to wear them both while kitting up and during the dive. Whatever your preference, there are plentiful corrective options available to ensure that everyone can experience the beauty and wonder of the underwater world.
Guidelines For Post-Dive Equipment Care
By Jessica Vyvyan-Robinson
If you own scuba equipment, knowing how to properly take care of it after a dive is crucial. Not only does good post-dive maintenance increase the lifespan of expensive equipment, but it also minimizes the risk of gear-related issues the next time you dive. Our equipment is our lifeline underwater, so keeping it in working order is of paramount importance. Basic rules apply to the post-dive maintenance of all scuba gear, including rinsing items thoroughly with fresh water after a dive, and allowing them to dry completely before being packed away. Dive gear should never be left in direct sunlight for prolonged periods of time, as sunlight can degrade, crack or fade materials, including neoprene and rubber. Specific considerations relate to particular pieces of equipment, most of which are listed below.
Like the rest of your scuba equipment, your regulator needs to be rinsed in fresh water at the end of the day’s diving. Make sure that no water enters the regulator’s first stage, as it’s internal components are susceptible to damage when exposed to moisture —allowing them to get wet will most likely result in an expensive trip to an equipment technician. Before rinsing, replace and securely fasten your regulator’s dust cap, first ensuring that the dust cap itself is dry. You can do this by using compressed air from your cylinder to blast excess water from the dust cap before fastening it in place, but that method’s not without detractors.
Instead of leaving your first stage to soak in fresh water, rinse it thoroughly under the tap; this will safeguard against water seeping past the dust cap. Alternatively, you can fully submerge your regulator if the first stage is still attached to a pressurized cylinder, which will prevent any water from entering the system. Do not press the purge button on either your primary second stage or your octopus while you are washing your regulator, as this will also allow water to enter the first stage. If you have hose protectors, make sure that you rinse underneath them during the cleaning process; similarly, move your low-pressure inflator connector back and forth to remove any salt, grit or sand. This way, even the least visible parts of your regulator will be kept corrosion free, and will continue to perform as they should. Once you have finished rinsing your regulator, hang it up and allow it to dry completely before packing it away.
When it comes to washing your BCD, it’s hugely important to remember the inside after having thoroughly rinsed the exterior. During a dive, salt water leaks into the BCD through the dump valves and the low-pressure inflator, and must be drained out during your post-dive maintenance routine. To do this, use a hose to flush fresh water into the BCD’s bladder via the low-pressure inflator, making sure to hold down the deflate button as you do so. Allow the water to flow into the BCD until it is approximately one quarter full, and then orally inflate it. This will allow the water to easily circulate around the inside of the BCD. Then, shake it to make sure that the water reaches every part of the jacket before allowing the water to drain through the dump valves, simultaneously rinsing them too. You can repeat this process several times before inflating the BCD partially and storing it. Ideally, you should keep your BCD hung up in a cool, dry place; the partial inflation will prevent the insides of the BCD from sticking together.
Wetsuit, booties, hoods and gloves
All of these items should be washed both on the inside and on the outside. It’s a good idea to use soap or disinfectant to eliminate any odors, but make sure that you buy one that’s appropriate for use on neoprene. Wetsuit soap is readily available at most dive centers or equipment stores; rinse it off with more fresh water once used. After cleaning your wetsuit and other neoprene items, hang them up to dry completely before packing them away. If you don’t, mildew and other bacteria will develop, degrading the quality of your equipment and causing it to smell. The best way to store a wetsuit is to hang it up, preferably on a purpose-built wetsuit hanger. Do not use wire hangers, as they will crease and mark your suit — the wider the hanger, the better. For transporting your suit or for storing it for short periods of time roll it rather than folding it. Folds can cause creases in the neoprene that may not come out, and make the suit uncomfortable to wear. It is also a good idea to lubricate the zips on your wetsuit or booties, ideally with zipper wax specifically made for this purpose.
Many divers overlook their cylinders when it comes to post-dive care, but they also need to be rinsed with fresh water. This prevents salt buildup and consequent corrosion, and also displaces grit and sand from around the tank valve; if left, these particles can make it difficult to turn your air on and off. You should never put a cylinder into storage either emptied or filled completely. When empty, the absence of pressure can make it easy for contaminants to enter the cylinder; if stored too full they can eventually crack over time. They should be stored lying horizontally, or in a secured upright position to prevent them from falling and becoming damaged.
Mask, fins and snorkel
Your soft gear is easily maintained; like everything else, it must be rinsed in fresh water, dried and put away carefully. Your mask should be packed in a hard case to protect the lenses from scratches and the mask itself from possible impact. Make sure that any other items that you store with your mask (e.g. dive computer, compass) do not bend, squish or deform the silicone; otherwise, your mask’s shape could be altered causing it to leak or become uncomfortable. Similarly, save the plastic inserts that come with your fins when you buy them, and replace during storage to retain the shape of your fins’ foot pockets. Do not store your fins by balancing them on their tips, as this can also cause distortion and diminished performance. Instead, keep them lying flat, or hung by the strap on a wide peg.
Each of your dive accessories has unique care requirements. Underwater cameras, for example, have a lengthy post-dive care regime. They must be left to soak for as long as possible in fresh water, to allow all salt to dissolve from the housing. You should gently work all of the housing’s moving parts to dislodge any salt, grit or sand stuck beneath them. Once you are satisfied that the housing is salt-free, you must dry it completely before opening it to remove your camera. You should remove your batteries and memory card from the camera, and make sure to wipe clean and lubricate all O-rings. Do not store your housing with the main body O-ring in place, as the constant pressure will eventually change the shape of the O-ring and reduce its ability to create a sufficient seal. Instead, remove the O-ring carefully, clean it and store it with the rest of your equipment in a sealed plastic bag. Strobes and underwater torches should be treated similarly — wash, dry, remove batteries, then clean and lubricate all O-ring.
When washing your dive computer, make sure to depress all the buttons while holding the computer underwater in order to flush salt deposits from beneath them. Rinsed and dry dive knives thoroughly, then apply a thin coating of silicone grease to the blade before storage to prevent rusting. All other diving equipment, including signal marker buoys, compasses, whistles and octopus attachments should be rinsed at the same time as the rest of your gear, and stored appropriately.
No matter how diligently you take care of your equipment, make sure to fully check and test your gear before use to ensure that it’s in full working order. Above all, remember that by properly looking after your dive equipment, you are allowing it to continue looking after you.
The Pros and Cons of Owing Your Own Equipment
Most divers will, at some point, have to decide whether or not to invest in their own gear; for many, the list of pros and cons can become convoluted and confusing. Dive centers, teaching organizations and retail outlets constantly extoll the value of owning one’s own equipment, but it’s sometimes difficult to know how much of their zeal has to do with improving your dive experiences versus making a profit. This article aims to explore the ins and outs of owning gear from an unbiased perspective, so that those thinking about purchasing their first mask, BCD or set of regulators can make an informed decision.
Divers considering purchasing equipment should ask themselves several questions first, including the extent of their commitment to the sport, how often they plan to go diving and whether the majority of their dives will take place at home or on vacation. A full set of gear can be expensive, and perhaps not worth the investment for someone who intends to dive only once or twice a year. However, for those who dive frequently, the costs of purchasing gear pale in comparison with the cumulative costs of repetitive equipment rental. When it comes to dive equipment, it is easy to spend huge amounts of money, but it’s also possible to buy a basic set of reliable, fully functional gear for a reasonable price. A basic set includes a mask, snorkel, fins, exposure suit, regulator and BCD, and the price for a set of mid-range equipment should total at around $1,000 to $1,500, not including a computer. If cared for properly, scuba gear can last for many years; therefore, if daily rental prices for basic scuba gear average between $25 and $60 depending on location, frequent divers can easily recoup the money spent on purchasing equipment. Additionally, the cost can be spread out — instead of buying a full set of gear all at once, start with the essentials (mask, fins, snorkel, exposure suit), and work up to the higher range items (BCD, regulators and dive computer).
Another cost of owning one’s own equipment comes into play for those who primarily dive abroad. Although luggage allowances for long haul or transatlantic flights tend to be a little more forgiving, the normal weight restriction for hold luggage is around 50 pounds, depending on the airline. An average set of dive gear will use up most of that allowance, forcing travelers to pay overweight or excess luggage fees. There are workarounds, including packing heavier items like regulators in carry-on bags and choosing airlines that offer allowances for sports equipment, but increasingly tight regulations mean that even these measures can incur additional costs. Traveling divers must weigh these additional costs against paying rental fees and reliance on unfamiliar foreign equipment, and decide which is the lesser of two evils for them personally. Some scuba manufacturers have come out with lightweight gear meant for dive travel, which can eliminate excess luggage fees. Those who opt for these models, however, should be aware that they are often only suitable for diving in tropical climates and may not be compatible with the more taxing conditions of colder, rougher seas.
Safety and Peace of Mind
Although the financial aspect of buying gear is the first concern for many divers, there are other, equally important factors to consider, including personal comfort, safety, health and convenience. Two of the biggest advantages of owning your own gear are fit and familiarity; when you buy gear, you know that it fits your shape and size, and you know exactly how it works. Often, those who rent gear have to put up with ill-fitting equipment that can seriously hinder their comfort. A mask that’s the wrong size can leak; a wetsuit that is too loose leads to rapid heat loss; a BCD that’s too small may not have sufficient lift to allow for positive buoyancy on the surface. In extreme cases, these issues not only lead to reduced enjoyment, but can also compromise a diver’s safety, particularly in the event that a diver’s movement is restricted such that he can no longer effectively perform skills. Unfamiliarity with dive gear can also be dangerous thanks to the subtle differences between different styles and brands. Knowing exactly where your dump valves are located on your BCD or how to dump your integrated weights could be the difference between diverting and exacerbating a disaster.
By owning and becoming familiar with your own gear, dealing quickly and effectively with an equipment-related emergency becomes like second nature. Similarly, good fit allows for maximum comfort and capability underwater, allowing you to focus on activities like photography or fish ID rather than gear adjustment. The peace of mind and enhanced safety you’ll feel when using your own gear is a main reason for doing so. When you rent, particularly abroad, you have no idea how the gear has been maintained, whether it has been recently serviced, whether the dive center in question has items available in your size, or who has used it before you. Uncertainties are eliminated when using your own gear, which offers heightened confidence in an environment where your safety depends largely upon your equipment. Additionally, in a sport where divers routinely spit in their masks, urinate in their wetsuits and cough through their regulators, being the first and only person to use your gear is a matter of personal hygiene.
Of course, owning your own gear involves some work that renting gear does not. Instead of emerging from the ocean and having your equipment washed, taken apart and packed away for you, you’re responsible for the day-to-day care and long-term maintenance of your gear. As well as rinsing your equipment thoroughly with fresh water after each dive, and packing, transporting and storing it in a way that will increase its longevity, you must also get your BCD and regulators serviced annually. Cylinders must be inspected visually and hydrostatically, and dive computer batteries must be changed manually or sent in to a technician for replacement after a specific amount of time or dives. Each of these inspections or services costs money, as do repairs after any damages occur. You’ll also need to allocate storage space for your equipment in your home, making gear ownership a commitment in more ways than one. However, many divers find that the time, money and effort that they put into maintaining their gear works as a good incentive to go diving more often, thereby getting the maximum use out of their investment.
Top 5 Reasons to Try A Scuba Group Trip
Posted By Megan via PADI
If you’ve never enjoyed the experience of a group scuba diving trip, now’s the time to sign up for one. Group trips offer many advantages and opportunities that you miss out on when traveling alone. Here are five reasons why you might want to sign up for a group trip:
1. Enjoy activities and locations chosen by experienced travelers
When planning a scuba trip in unfamiliar territory, it’s difficult to know where the best dive spots and operators are located. If you go on a group trip, all of the locations, dive operators and activities are chosen by experienced, knowledgeable travelers so you can enjoy the best experience possible.
2. Save money
Traveling can be expensive, especially when you travel alone. Going on a group trip is cheaper than booking an individual flight, which means you can spend less money on the travel fees and more money on fun souvenirs and experiences.
3. Great photos and videos of the experience
If you go on a scuba trip with a group, there will be other travelers who will shoot photos and videos, which will make it easier to show others some of your memories from the trip.
4. Create long-lasting friendships
Just like the summer camp you went to as a kid, group trips allow you to meet new people and create long-lasting friendships. A group trip is one of the best ways to meet new people and find new dive buddies. We often hear about folks who live in different parts of the world and meet up once or twice a year just to go diving.
5. Network with other guests
You never know how the connections you make can affect your future. Networking with the right people can open up opportunities for you down the road, whether it’s in your personal or work life. By signing up for a group trip, you are not only making new friends, but you are also making new connections.
Why Becoming A PADI Rescue Diver Is Seriously Fun
By Jessica Vyvyan-Robinson
Divers often describe PADI’s Rescue Diver course as the most rewarding of all their training experiences. Becoming a Rescue Diver not only teaches you how to prevent dive accidents and emergencies — and how to manage them should they arise — but it also consolidates your skills and experience from earlier courses, making you a more confident and accomplished diver. More than any other course, Rescue Diver training increases awareness of the dive environment and the factors that affect diver safety. Learning how to interpret and react to those factors makes the course both fulfilling and fun. It is designed for anyone interested in expanding on the basic rescue skills that they learned in their entry-level courses, with the goal of becoming equipped to help themselves and others in an emergency situation. It is also a mandatory step in becoming a PADI professional. There are a few prerequisites to enrolling in the course: potential Rescue Divers must be at least 12 years old, and have completed their PADI Adventure Diver certification with Underwater Navigation as a mandatory specialty. In addition, candidates must have undergone EFR Primary and Secondary training within the last 24 months, although this can be done in conjunction with the Rescue course. The Rescue course will teach you how to adapt the skills learned during EFR training to situations pertinent to diving.
Unlike previous courses, the Rescue Diver course involves relatively little time spent underwater. Instead, there are two main components, the first of which is a theory section comprised of five knowledge reviews and a final exam. Divers will explore a range of topics including the psychology of rescue, recognizing diver stress, and preparing an emergency assistance plan for a specific dive site. The second component of the course is devoted to skill mastery. While that may not sound particularly interesting, this section involves a lot of teamwork and role-play, which demands constant awareness and quick thinking. The skill sequences are challenging, adrenalin-inducing and above all, fun. The practical section of the course is divided into three sections: self-rescue skills, ten rescue exercises and two rescue scenarios. The self-rescue skills are basic and should be familiar from earlier courses; they include cramp release, establishing positive buoyancy at the surface and using an alternative air source. As simplistic as these skills may seem, they are effective ways of alleviating problems that without proper attention could become far more severe. Much of the Rescue Diver course is dedicated to preventing accidents from happening in the first place or to mitigating them in their early stages. It is always preferable to avert an emergency rather than to face one.
The ten rescue exercises are the backbone of the course, and teach individuals how to react to a variety of potential accidents or scenarios. They include learning how to appropriately assist tired and panicked divers, how to respond to distressed divers from shore and underwater, the most efficient ways to search for a missing diver, proper exiting techniques, and how to administer oxygen and in-water rescue breaths. Mastery of these skills could one day mean the difference between tragedy and survival; by knowing how to perform them effectively you become equipped to save lives. Your instructor will have assistants simulate these scenarios at any given time throughout the course, often without warning. You will be expected to react to them quickly and efficiently, as if the accident had occurred in real life. The skills that you learn as a result of this training will be put to the test in the rescue scenario section of the course, when you will be required to react to an unresponsive diver at the surface and an unresponsive diver underwater, performing the necessary steps for a rescue from start to finish.
Most divers who complete their Rescue Diver training will never have to provide assistance in the aftermath of a dive accident. Thankfully, serious dive accidents happen with a scarcity that means the most valuable skills divers take away from their training are normally preventative ones, such as recognizing and managing diver stress or eliminating vertigo before it becomes a problem. However, knowing that you are able to cope with an emergency not only makes you a better buddy, but also a generally more confident, capable diver. It is important not to let your newfound skills stagnate; keep them up to date and refreshed with frequent practice. That way, whatever situations arise, you will be sufficiently equipped to deal with them in the safest and most effective way possible.
Nitrox For Beginners
By Jessica Vyvyan-Robinson
Although nitrox has been used for recreational diving for almost 25 years, it is still often misunderstood. As an instructor, I’ve found myself correcting countless students who are under the impression that nitrox enables a person to dive deeper than normal air — just one of the common misconceptions about nitrox diving. Although specific training is required before diving nitrox for the first time, these basic facts will help to make more sense of what it is and what it can do for you.
What Is It?
Quite literally, nitrox refers to a mix of nitrogen and oxygen, regardless of the percentage of each in the mix. The nitrox we use while diving is more properly called enriched-air nitrox, and refers to any blend of nitrogen and oxygen in which the oxygen concentration is greater than that of normal air. This means an oxygen level of 22 percent or higher, although the most common enriched-air nitrox blend is 32 percent. The recreational diving limit is 40 percent oxygen.
What Does It Do?
As every entry-level diver knows, increased pressure at depth causes the nitrogen in the air we breathe to be dissolved into the bloodstream. The time that we can spend underwater is limited by this nitrogen absorption — as we dive deeper and for longer, we absorb more nitrogen at a greater rate. Our no-decompression limit correlates to the amount of nitrogen our bodies can absorb before we must perform compulsory decompression stops or suffer the consequences of decompression sickness.
Enriched-air nitrox slows down the rate at which nitrogen dissolves into our bloodstream, because there is less nitrogen available to be absorbed from the mix that we’re breathing. The higher the percentage of your enriched-air blend, the more nitrogen is replaced with extra oxygen.
There are several reasons divers use enriched-air nitrox. One of its biggest benefits is an increased no-decompression limit, which means longer bottom time. The lower percentage of nitrogen in the nitrox you’re breathing means your bloodstream is also absorbing nitrogen more slowly. For example, on normal air a diver has a no-decompression limit of 50 minutes at 60 feet; using a 36 percent enriched-air mix at the same depth will extend this limit to 130 minutes. In terms of increasing bottom time, enriched air is most useful for depths between 50 and 100 feet; any shallower and no-decompression limits are already so long that divers usually have no need to extend them.
Surface intervals are usually shorter on nitrox as well. Since there is less nitrogen to off-gas, a diver on enriched air will be able to re-enter the water sooner than a diver using normal air after completing the same profile. This also means that divers using enriched air typically have longer maximum bottom times on repetitive dives, and less off-gassing means that enriched air divers are often less tired at the end of the day than divers using normal air. Enriched air can be a valuable safety buffer for divers who choose to use it while following normal air tables, computers, profiles and procedures. Doing so creates a considerable conservative margin that further reduces the risk of decompression sickness, and may be advisable for anyone who may be susceptible to it, such as those who are tired, overweight, older, have suffered decompression sickness before, or are diving with injuries.
Myths, Considerations and Dangers
Although the benefits of diving with enriched air are significant, doing so also involves certain risks. One of the most common misconceptions about enriched air nitrox is that users can dive deeper than with normal air; in fact the opposite is true. Under pressure, oxygen becomes toxic. The percentage of oxygen in normal air (21 percent) only becomes toxic at depths greater than the recreational limit, but the increased percentages of oxygen in enriched air mean that toxicity can become a problem at much shallower depths. Toxicity causes convulsions that put a diver at risk of losing his regulator and subsequently drowning. However, enriched-air courses teach divers how to work out their maximum operating depth using the percentage and partial pressure of the oxygen in their mix. As long as the maximum operating depth is adhered to, oxygen toxicity should not be a problem.
Oxygen also requires caution in the sense that it is an exceptionally flammable gas. Although standard scuba equipment is safe to use with air blends containing up to 40 percent oxygen, the process by which an enriched-air cylinder is filled often involves much higher concentrations. Partial-pressure blending exposes the cylinder to pure oxygen that is later diluted with normal air, and cylinders that are not treated for exposure to such high levels of oxygen can explode. Therefore, any part of the cylinder that comes in to contact with pure oxygen needs to be “oxygen clean,” and cylinders used for enriched air and normal air are not interchangeable. Enriched-air cylinders require decals or stickers to differentiate them from normal ones; they should be serviced annually.
There are a few other equipment considerations to bear in mind when considering enriched-air diving. Before each dive, you are personally responsible for checking the percentage of oxygen in your cylinder. If it is even slightly off, your maximum-operating depth calculations will be too. To check, you will need an analyzer, and although you can usually borrow one from your dive center, it’s a good idea to have your own if you intend to dive nitrox regularly. If you dive with a computer, you need to make sure that yours has enriched-air settings and correlates to the details of your mix before beginning each dive. Remember that enriched air does not improve air consumption, and neither does it give immunity to decompression sickness. Continue to check your gauges, depth and time limits as often as you would when diving on normal air.
With these precautions and the necessary training, enriched-air diving is a fantastic way to get the most out of your diving experience. You’ll spend more time in the water, and less time waiting to get back in.
Should I Get A Dive Computer
By: Charles Davis
Dive Computers are a Sign of Dedication
Each diver will have to decide for themselves if a dive computer is a must have, nice to have or a waste of money. Most serious divers swear by their computers but in reality they were most likely diving for quite a while before purchasing their computer. Dive computers are relatively new in the overall scope of scuba diving and will most likely be your most expense purchase, even more than the training and basic equipment. The variety and capabilities of the different computers on the market are staggering. However, before you even start sorting through the different manufacturers and models, you really need to determine do you need one and how great is the need. You learned the dive charts in your training and they have served you well. When you plan your dive, you look up your limits and adjust your plan to ensure that you stay within the safe limits. Before your second dive, it is back to the charts to look at your residual times. When you start doing dives that are a little more difficult to plan such as a multiple level dive, then you can start using the dive wheel. However both require you to stay within the plan. Also they assume that you are at the same depth for the same amount of time that you calculated.
What is a Dive Computer
Before getting to involved with the topic, I think a brief definition should be included. While there are numerous features on different models we will stick to the basics. Technically it a very difficult process. The computer is able to take its own pressure reading and can accurately keep time. Inside the dive computer are what are referred to as compartments. The number varies by model, but they are calculations designed to mimic the effects of nitrogen on different type of tissue within your body: such as fat, muscle, tendons and so forth. Tissue types absorb and release nitrogen at different rates. Every two seconds or so the computer take a pressure reading, calculates the lapse time and updates the compartments. Using a logarithm based on dive tables it calculated and displays your NDL and other information. The computer is calculating on the performed dived not on how it was planned. Computers are not perfect, there are items that affect the absorption rate that the computers can not measure, such as your activity level, the presence of drugs or alcohol in your blood or your level of hydration. The use of a dive computer allows you to maximize your time underwater using real time data while keeping you within a safe profile.
What is Your Normal Dive
The types of dive you do will be a factor whether it is a must have, nice to have or a waste of money to get a dive computer. If you only dive infrequently and at shallow depths then a dive computer may not be necessary for you. A dive at 30 or 40 feet can easily be managed using the dive tables. If you are doing dives around 60 feet but at a single depth then there may be some use for a computer but it is still limited. If the 60 foot dive is also able to be done as a multilevel then you will see some benefits of a computer allowing a little extra dive time. It is not unusual to an additional 15 or 20 minutes to a dive that goes to 60 feet but returns to 30 feet during the dive. Once you start diving beyond 60 feet then a computer becomes a very useful tool.
If you have not used a dive computer yet, I would suggest you rent one for a few dives. Many dive centers have computers for rent. Some center are even making a computer a requirement for deep dives. Deep being defined at below 60 feet. Plan the dive as you normally would but, use the readings from the computer during the dive. Afterward compare what you were able to safely dive with the times listed in the dive plan. This should help illustrate the value of the computer for your diving style.
If you are thinking of getting a computer, project how many dives will you do in a year, also how many of those are deep dives. Also take the cost of the dive computer you are interested in and divided it by the cost to rent the computer. This will tell you how many dives it would take to pay for the computer based on the rental cost. These three number should show you the economic benefits of buying instead of renting.
Dive More Safely
Dive computers have helped many divers maximize bottom times while still staying in a safe range of risk. They are also able to warn a diver that has exceeded his NDL and to provide guidance to reduce the risk with decompression stops. Given the serious injuries that can result from DCS, a dive computer should be considered for anyone who dives near the edge of the dive tables maximum time.