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dive-log

How Logging Your Dives Can Make You a Better Diver

Here are a few items you can include in your logbook to help you stay organized and honest, track progress, and work on self-improvement as a diver.

The-importance-of-course-prerequisites2

Why are Prerequisites Important in Technical Diver Training?

Prerequisites can be found in the Standards and Procedures for any course you are interested in taking.

Clipping: A Vital Skill for Fluid Diving

This article touches upon efficient ways to operate the ‘cursed’ clip and offers a few ideas on handling known as ‘Clip Management’.

6 Key Differences in Diving a Dry Suit vs a Wetsuit

by: Jim Lapenta SDI/TDI Instructor
dry diver
Much of the advertising one sees for diving involves warm water and divers in swim suits or thin wetsuits. It can be a bit of a shock to those divers who were certified in warm water to make a pilgrimage to a cold water location. For those of us who dive and teach in much of the northern hemisphere, talking about the differences is much like talking about how to choose a mask.

We are often asked about the differences between diving wet and diving dry. Other than the obvious answer – “you don’t need to dry anything but your hair after the dive” – there are some key differences.

  1. Warmth. This is probably the most important reason to decide to dive dry. You know that neither a wet suit nor dry suit actually keeps you warm. What they do is slow the amount of heat loss. Wet suits do this using a layer of neoprene and a thin layer of water trapped between that and the skin. Dry suits use air and a combination of undergarments. No water to take heat away if a seal is lost and allowed to flush through the suit. With dry suits you can add layers of insulation to slow the loss of body heat.
  2. Buoyancy. Wetsuits compress with depth and lose some of their inherent buoyancy. Dry suits allow the diver to add air and compensate for the increased pressure at depth. As the wet suit compresses, it gets thinner and loses insulating capacity. The dry suit does not.
  3. Weighting. Once a diver has become proficient with a dry suit, over-weighting is not as much of a concern as it is with a wetsuit. As a wetsuit loses buoyancy at depth, a diver can become seriously over weighted due to suit compression. With a dry suit, the amount of buoyancy the suit offers stays more or less constant since the diver has the means to adjust for the increased/decreased pressure.
  4. Varying conditions. A large benefit of a dry suit is the ability to use the suit in various conditions. A wetsuit does not offer the flexibility of a dry suit to add or subtract undergarments to suit the water/surface conditions. Many divers use their dry suit year round, from warm water locations to under the ice in winter.
  5. Purchase cost. At one time dry suits were prohibitively expensive for the average diver. One could purchase several wetsuits for the cost of one dry suit. They often had to if diving in a wide range of water temperatures! With the introduction of new materials and manufacturing competition, a quality entry level dry suit can be had for roughly the same price as a higher end wet suit. By varying the undergarments the diver can also avoid having to buy several different thicknesses of wetsuits. One dry suit will work in numerous environments.
  6. Cost of ownership. Once a diver buys a wetsuit there is very little maintenance other than proper rinsing. Dry suits require seals to be replaced, leaks attended to, boots or socks replaced, and maybe even the zipper. These costs may be offset by the life of the suit. Dry suits, with proper care, can last 15 – 20 years or more. This is using the suit on a regular basis- say 100 dives a year. A wetsuit seeing that much use may last five years. In the long run, a drysuit may actually be less expensive. Dry suits often hold their value for resale. Used wetsuits get tossed. Used dry suits are sold to offset the cost of a new one!

For more on the differences/ benefits of dry suit diving, contact your SDI/TDI/ERDI Instructor to see if it’s a wise choice for you.

Survivor or Statistic… Which One are You?

by Jon Kieren:
tdi diver and reefDive enough and you’re bound to have a few “incidents.” Technical dive enough and you’re almost certain to have at least a couple of “hits the fan” moments. TEACH technical diving at ALL, and it’s a whole other level of “pucker factor.” Knowing that we are going to have some sort of equipment malfunctions, environmental/navigation emergencies, and will just simply make mistakes at some point in our technical diving careers, how do we avoid becoming a diving fatality statistic? Follow the rules, keep things simple and conservative, stick to your training, practice, and stay calm.

    • Follow the rules – In technical diving there are a lot of them. They are there for a reason, usually because someone (or several people) died. Whether it’s gas volume requirements, gas analysis, cylinder labeling, depth/penetration limitations, equipment requirements, pre-dive checks, equipment maintenance, etc., there simply is not a dive that is worth breaking these rules and risking your life. Technical diving carries enough inherent risks as it is, and these rules are there to help mitigate those risks. Don’t push it, and don’t get complacent.

 

    • Keep things simple and conservative – We’ve all read the stories. Divers who tried to go beyond what a reasonable plan would allow and came up short. Keep dive plans and objectives as simple as possible, and plan conservatively.

 

    • Stick to your training – You paid an instructor (probably several by this point) a lot of money to train you how to dive, don’t let that money go to waste. What’s the point of training if you’re going to ignore what you were taught anyway? Going beyond the limits of your training can place you in situations you are not prepared to handle, and can (and often does) lead to fatalities. Don’t put yourself in that position, stick to your training.

 

    • Practice – Dr. Anders Ericsson’s research on expertise found that it takes 10,000 hours of deliberate practice to become an expert at almost anything. Since then, it has been more refined and determined that this practice must include proper evaluation, feedback, correction, and reward to truly be effective. Try and put that into the context of diving. 10,000 hours of practicing valve drills before you become an expert. You better get in the water.

While 10,000 hours is obviously not a realistic value, it certainly puts things into perspective, doesn’t it? How many of your buddies consider themselves “expert divers?” How many hours do they have under water? The point here is not to shoot anyone down or deflate anyone’s ego, but instead to point out that everyone needs more practice. It is often said that in a true emergency situation, the BEST you can possibly expect to respond is the WORST that you perform in practice. Think about your last skills dive, the worst you performed any of those skills is how you will react in an emergency. Would you survive? Just because you went through a great Deco Procedures course, doesn’t mean you’re now an expert at decompression diving. You have a long way to go, and have only just begun to develop those skills.

  • Stay calm – In technical diving, panic kills. Plain and simple. If you allow yourself to go into “flight” mode in an emergency, you will become a statistic. That’s pretty heavy stuff considering we’re doing this for fun, right? Well, panic is the brain’s natural response when someone is beyond their comfort zone. A scenario we use to demonstrate the comfort zone with students is to ask them at their most vulnerable moment (maximum depth/penetration, near turn pressure, separated from the team, etc.) to mentally put themselves in the worst possible case scenario, like a catastrophic gas loss or silt out, and pay attention to their heart rate. If your heart starts to race just thinking about it, you’re probably outside of your comfort zone and should turn the dive. Knowing the limits of your comfort zone is extremely important and should be taken seriously on every technical dive. If there are any complications just before or during a dive, you need to re-evaluate your limits knowing that the error chain has already started. Each mistake or problem on a dive adds a link to this chain and reduces your comfort zone, and the likelihood of you staying in control in an emergency begins to vanish. Staying calm and within your comfort zone will drastically increase your chances of survival in an emergency by allowing you to rationally solve the problem instead of bolting for the surface.

We’re all in this to have fun, but chances are we’re going to run into a few problems along the way. As a technical diver you’ve been trained and given the basic tools to resolve those problems. As long as you stay within your comfort zone, keep your skills sharp, follow the rules, and try to keep things as simple as possible, you should be able to keep your name out of the accident reports.

6 Skills Every Technical Diver Should Master

Whether you are just starting your TDI Intro to Tech Course, or have over 200 Advanced Trimix dives, these six essential skills should be practiced on every dive.

Why Divers Do Stupid Things

by Mark Powell

Why do divers do stupid things? Well the short answer is because they are stupid. Now I know that the majority of the readers of this article are going to be divers and it’s not usually a good idea to start off by insulting your audience but bear with me. If you look at some of the recent diving incidents that have occurred such as the tragic double fatality of a father and son who died while cave diving on Christmas day, or the diver who refused to analyse his gas an ended up breathing 100% oxygen at 30m or the rebreather diver who jumped in with oxygen, diluent and handsets all turned off then you can see why I might say that. The British Sub Aqua Club publish a summary of diving incidents every year and a brief glance at this will show that dives do a whole range of stupid things. Not only that but they do the same stupid things over and over again. Most of the mistakes made each year are the same as the mistakes made the previous year. The short answer is that divers do not follow their training. It would be very easy to stop the vast majority of diving accidents if we could just force divers to follow their training. If you do what your instructor taught you during your course then you will avoid the vast majority of problems that occur. The thing is that you already know that, I know that, everyone knows that and yet hundreds of divers every day do things that break what they were taught in their training.

Is this because divers are genuinely stupid? or is it because they just act as if they are stupid? I believe that divers do stupid things because they are human and humans make mistakes. However that doesn’t mean that mistakes are inevitable. If we understand why we make mistakes we can potentially avoid them. If we recognise that each and every diver has the potential to make mistakes then maybe we will be a little more careful and a little less complacent.

We all have the potential to do stupid things because we sometimes get complacent, because we rush, because we are not very good at assessing risks, because we are often over optimistic. We do not always call a dive when we should, letting multiple little problems build up until they become a major incident. We trust our own powers of observation and can easily get fooled into trying to solve the wrong problem. Finally we often let other people influence us unduly.

I have tried to bring some of these ideas together and have given a number of talks on this topic at dive shows throughout Europe and the US. The video above was shot at TekDiveUSA (www.tekdiveusa.com) in Florida recently. This conference brought together technical divers from all over the world to discuss exploration, diving medicine and diving safety. As part of the conference I was asked to put together a short film which summarised why divers do stupid things. I hope this film helps explain why there is always a risk that we might do something stupid and hopefully will help you to avoid doing anything stupid in the future.

Deep Diving is an Experience, Not Just a Number

by Dr. Thomas W. Powell:

TDI Diver Bill Mac

photo credit: Bill Mac

In the diving world, a unique few choose to push their personal limits. This may include diving deeper, penetrating wrecks, or even diving with advanced equipment. With that being said, one may view going deeper as setting a new depth record. While some divers want to set private or universal depth records, most divers choose to go deeper for the experience. They may be seeking to discover what exists at depth, or they may want to see a wreck that sits outside of recreational diving limits. The truth of the matter is, actual depth is often not the real objective. Instead, depth is a factor the diver must understand and recognize during planning. Divers who love this sport focus on the experience, not just a number.

Despite technical diving being a complex realm, any diver can enter into it. However, one must keep in mind, factors such as the equipment, training, planning, and even price tags are different. These changes are all part of the “deep experience.” To begin, one must look at the equipment. Deep or technical divers often need more gas, bottles with mixed gas, multiple regulators, items like manifolds and doubles bands, mixed gas computers, side-slung or side-mounted cylinders, and redundancies across the board. This need for gear leads each individual diver to search for what works best for them, in regards to the most desirable items and their configuration.

Second, a diver seeking to go deeper and have more technical experiences may(should) seek out advanced training. This training introduces mixed gases, extended range capabilities, equipment configurations, as well as oxygen-based physiology and how it relates to decompression. To accomplish this training, a diver will often research what facilities and instructors he or she can best learn from. (Find a TDI Facility/Instructor here) This again, is all part of the “deep-diving experience.” Dive professionals and dive shop owners must remember that the experience does not just take place underwater. If the dive professionals involved work to provide the best possible experience, the diver will remain happy, the business may recognize more profit, and that same diver may become a loyal customer.

Third, the planning changes for the deep/technical diver when compared to recreational diving. During training, technical divers learn that emergencies may involve hard or soft ceilings. For this reason, the diver must learn how to “bail out,” or safely return to the surface using gasses carried to depth. This need requires the diver and his partner or team to develop a bailout plan for specified depths throughout the dive. If an instructor teaches the diver to be competent and comfortable in this task, the diver is more likely to enjoy it, and look forward to planning deeper dives. Again, quality and competent training will build a better diver who seeks to actively use the knowledge he or she has gained

Fourth, the price tag associated with technical diving can grow in comparison to the prices seen in recreational diving. The experience provided by instructors, boat operators, shop owners, and even other divers will make the expenditures less painful. However, if the diver develops a passion for technical diving, then the cost is justified.

Finally, technical diving skills open up a whole new world for divers. The diver can go places and see things that other divers may not have the knowledge or capability to safely see. Hidden wrecks, deeper marine life, and unique underwater formations become available for technical divers. In certain cases and with proper training, technical divers may even be able to explore places that others have never ventured. “Deep” is a factor related to technical diving, but only part of the overall experience.

Technical divers maintain a certain pride factor within their personalities. They have taken a step that few others choose to take, and for this reason, they enjoy the adventure of deeper technical dives. They also enjoy using complex planning and specified gas mixes to get to these deeper depths. Rather than just enjoying the marine life, diving becomes a complex adventure that demands close attention to detail, extensive planning, and thorough training. If the journey is positive from start to finish, the diver will get the complete experience. This “experience” is what keeps divers wet and encourages them to move forward within the world of scuba.


– Dr. Thomas W. Powell, Owner/Instructor Trainer – Air Hogs Scuba, Garner, NC

Speeding up Decompression – Tips & Tricks

by Dr. Thomas W. Powell:

2 trimmed divers in deco

photo credit: Thaddius Bedford

For the technical diver, decompression is an event that cannot be avoided. To go deep, and stay longer on an open circuit rig, you are going to go beyond your no decompression limits. With this requirement being recognized, decompression periods can be tedious and long, depending on the type of diving performed by the diver. The reality is that an individual cannot reduce decompression stop times without altering a dive plan. To make decompression periods more enjoyable however, a diver can find various activities to pass the time in an efficient and useful manner.

Some ideas for expediting a decompression stop may include:

  1. The first action a technical diver can perform during a decompression stop involves working on skills. This is a good time to set a line marker as a visual reference and practice skills like hovering, trimming out, and even kick styles like the back kick. A decompression stop is a period during which a diver must stay at a certain depth on a certain gas. The objective is to stay at a specific depth, which makes hovering in a trimmed out position a great skill to practice. For this reason, the time should not be wasted, and it is a perfect opportunity to work on becoming a better diver.
  2. Second, a diver may enjoy certain modern advances in technology. This may seem excessive, but I was recently speaking to a dive professional and rebreather diver who watched his students on a decompression stop. They gathered iPads in waterproof cases, and from their decompression staging location, began to read. They had literally prepped their equipment to allow them to read books while waiting out a decompression cycle. This may seem to break from the idea of, “getting away from it all while underwater,” but it is an effective means of passing time during a decompression stop in an enjoyable manner.
  3. The third way for a diver to pass the time during a decompression stop is through exercise. Most divers recognize that strenuous exercise during a descent or dive can cause an elevated heart rate, increased blood pressure, and therefore and faster on-gassing. Conversely, the Divers Alert Network (2014) states that exercise during decompression stops can aid in the off-gassing of inert gasses. Essentially, light exercise can increase your body’s ability to decompress. Despite this factor, the exercise performed must be mild. The Divers Alert Network also states that too much exercise can cause bubble formation, similar to shaking a soda bottle. This bubble formation can be problematic, and put the diver at risk. A safe and effective example is swimming around the line while working on trim.
  4. Fourth, a diver can play a game with his or her buddy or team. This could be something pre-planned using wet notes or some form of game (like cards) left at the decompression stop location during descent. A game will focus the mind and pass time in an efficient manner. This type of activity can also allow for work on hovering skills. If the divers involved are trimmed out, holding cards, and monitoring the actions of others while maintaining depth, the divers are both having fun and practicing skills.
  5. This final method for speeding up decompression stops involves the ultimate activity for a technical diver. An individual can begin planning out a future dive. Essentially, the diver can even plan a future dive to the same location, planning times at depth, bailout procedures, and gas requirements on his or her wet notes. This action would actually make the best use of time and allow the diver to hone his or her skills at working tables and math problems on the fly, underwater.

Divers always seem to be looking for fun and excitement at every turn. This desire is magnified in technical divers. Decompression stops are a necessary break required any time a diver passes his or her no decompression limit, especially if this passage is performed on purpose in a technical plan. If a diver must take a deco stop, the time can be used in an effort to improve personal skills while enjoying his or herself. The reality is that a diver must determine what works best for his or her own personal needs. The goal is to be safe, enjoy the sport, and pass the time in the best manner possible.


Dr. Thomas W. Powell – Owner/Instructor Trainer (SDI/TDI/ERDI) – Air Hogs Scuba, Garner, NC