Browsing Category Education
How can I communicate effectively underwater?
There are 5 main ways that divers communicate underwater.
What are they and how can we use them most effectively?
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Light
A handheld torch which you can signal and get attention with.
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Hand signals
Divers all know basic hand signals from when we learned open water.
Sign language for divers.
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Touch
Touch contact is also a way that we can communicate.
Holding on to another person’s arm or hand, or tapping them on the shoulder are both effective ways of touch communication.
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Sound
Tapping on your tank, or making a sound with your hands is another common way of getting attention.
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Writing
Writing on a slate or wet notes, provided you have these kinds of equipment with you, is also a very effective and unambiguous way of communicating.
Breaking it down
Now, each of these methods has it’s pros and cons. Let’s explore them all.
- 3 of the above methods are visual in nature (light, hand signals, and writing)
- 3 of them require close proximity (hand signals, touch, and writing)
- 2 of them allow communication over a distance (light and sound)
- And only 1 is unambiguous (writing)
Attention seeking divers
One of the most common communication types required is getting another diver’s attention.
After which you can continue to elaborate with other forms of more unambiguous types of communication.
Over a distance, only light and sound work for this purpose.
However, sound is non-directional, whereas light is highly directional.
For me, I think a torch should always be available as a communication tool, for this exact reason.
Sound travels well, but unless you are already in visual range, it’s not going to work so well.
I’m sure you’ve had the experience of being in the water when someone is banging their tank, and you have no idea where it’s coming from.
In bad visibility, sound communication is definitely not as effective as a light.
Awareness, always awareness
However, if a team is diving well, with good diving etiquette, maintaining good relative positions and line of sight, then a good dose of awareness is all you need to get someone’s attention.
A good habit I always teach my students regardless of certification is to constantly look around at the other divers in the group.
When driving a car, you should be checking your mirrors every 20 secs.
Similarly, you should be doing the same thing while diving.
If we can all adopt this habit, then I won’t need to worry about getting someone else’s attention.
I’d only need to keep staring at that person, and I know that in 20 secs or so, she will look right over at me!
Now, how much more comfortable would that dive be?
Knowing that you can count on your teammates looking out for you every minute!
The 5 main trends in decompression
Decompression theory has a reputation of being complicated and hard to learn.
In my experience, it doesn’t have to be!
We can reduce the complexity if we just keep in mind these 5 main trends of decompression theory.
*Note: this article isn’t meant to be a thorough understanding of decompression theory. The main goal is to simplify decompression theory in layman’s terms.
Trend 1 – The deeper you go, the more nitrogen you take up because of the higher pressure of the gas you breathe.
Whenever you scuba dive, you are breathing gas at ambient pressure.
This means that you are breathing more molecules of nitrogen for every breath that you take when deeper than sea level.
The deeper you go, the more molecules of gas you take in, even though the volume of gas in each breath doesn’t change.
This extra nitrogen is absorbed into your body and eventually, will need to be released when you ascend to the surface.
Trend 2 – The longer you stay, the more nitrogen will get absorbed into your tissues.
If you spend longer in the water at depth, then the more breaths you will take and more nitrogen will be absorbed into the body.
Trend 3 – If the gas you use has a lower nitrogen content, then there will be less nitrogen available to be absorbed into your tissues.
Let’s compare two gases, one with a lower nitrogen fraction than the other.
Which gas will cause more nitrogen absorption into the body given that all else is the same (number of breaths taken, depth and duration of dive)?
I think the answer would be fairly obvious.
This basic idea is the reason why Enriched Air Nitrox (EAN) gas mixes exist.
A commonly available EAN mix is 32% oxygen and 68% nitrogen.
This provides an 11% reduction in nitrogen content as compared to normal air.
Choosing an Enriched Air Nitrox mix is always a good idea for reducing your decompression obligation.
Trend 4 – The slower you ascend, the more excess nitrogen will leave your body.
A less commonly known trend would be how fast you surface from each dive.
By ascending slower, you’re allowing time for the nitrogen in your tissues to leave your body.
A faster ascent rate also causes any gas bubbles in your body to expand.
It will also cause the release of excess nitrogen as bubbles instead of being transferred back to the lungs for exhalation.
By slowing down our ascent rate, we can control the size of these bubbles and at the same time allow nitrogen to work its way out of our tissues.
Trend 5 – The longer the surface interval, the less nitrogen you will have before your next dive.
Once on the surface immediately after a dive, there will always be some excess nitrogen in your tissues. This is the concept of residual nitrogen.
The more residual nitrogen you have in your system, the more conservative you should be on your subsequent dive.
Thus, the longer you stay on the surface before your next dive, the more time the excess nitrogen has to leave your body.
The less nitrogen in your system, the better it is for your decompression obligation on your next dive.
Putting it all together
So what does this mean for divers?
How can we navigate the complexities of decompression while staying safe?
The 5 main trends in decompression
General rules
Once you understand these trends, then how do we put everything together?
I consider these 5 trends as adjustable variables in my overall decompression obligation.
I can tweak or adjust one or more while leaving the others in place, allowing me to ‘adjust’ my decompression obligation based on the dives I’m planning to do.
Planning a day of diving
Keep the number of dives per day to 3 (roughly 9 am, 1 pm, 4 pm, with a break for lunch).
You can add on a dawn dive and a night dive as these would extend the beginning and end of your diving day.
Let’s look at how this relates to a decompression table.
Let’s look at a PADI RDP table and trace a line that follows a surface interval of 1 hour and 2 hours.
The PADI RDP table showing a 1 hour and 2 hour surface interval line
We can notice that we end up with a pressure group of J and C respectively if we have a starting pressure group of Z.
With a more realistic pressure group of between G and M, you would end up with a pressure group between A to E after a 1 or 2-hour surface interval respectively.
With a 2-hour surface interval between each dive, 3-day dives are all that you have time for anyway.
What about if you happen to miss a safety stop?
If you do happen to miss a safety stop, then change up one of the other parameters on your next dive.
You could do a longer surface interval, do a slower ascent, stay shallower, or dive for a shorter time.
You can still change the depth and length of your dive if you are on a fixed dive schedule.
Always ascend slowly
For ascents, I would always take my time to ascend, limited by the gas that you have remaining.
However, I only do this after I’m shallower than 6m. Any deeper than that and you would still be taking on nitrogen into your system.
If there’s a nice shallow reef with things to look at while you are at your safety stop, and you also have plenty of gas left, then why not stay and enjoy the view?
Personally, I would ascend slowly (9 m per min) to half of my depth, then move at 3 m per min up to 6m.
Once at 6m, provided the team has gas, I’d take my time and enjoy the sights until everyone’s computers have cleared or we get bored!
We’ve been known to hang around at 6 m for 15 to 20 mins!
And always dive Nitrox!
As for gas choice, if you ask me, there’s no reason to dive air if there’s nitrox available.
If I can reduce my decompression obligation just by changing the gas I dive with, it’s a no-brainer.
There’s so much benefit in diving nitrox, and these days it doesn’t cost much either.
There you have it!
Some simple and easy to remember rules for planning a day of diving while keeping yourself safe.
Now, get out there and know your decompression obligation!
What should I focus on now that I’m certified as a diver?
Congratulations on being a diver and joining the club as an adventurer!
After getting certified as an Open Water diver, the choice of courses, trips, and equipment seems endless.
What’s the next adventure you should embark on? And what should you spend on to maximize your enjoyment?
More diving?
Getting more diving done is always a good choice.
Your enthusiasm for diving is still running high, and there are so many places to go and things to see.
There are a lot of different types of diving out there, like strong drift dives, altitude diving, muck diving, liveaboard diving, underwater photography, etc.
Divers preparing for a boat dive
Gaining experience in all of these different diving environments is necessary to make a well-rounded diver.
However, with heavy travel expenses, and expensive resorts and boats, perhaps being more equipped would help with your overall experience?
More equipment?
What about buying new dive equipment for your next adventure? Would that be a wise way to spend your resources?
I think personal dive equipment is important when the fit is a primary concern like wetsuits, booties, and masks.
These can be purchased early on, as long as you find something that is suitable for where you plan to dive.
These items are not very expensive, and with a good fit, they will ensure you remain comfortable on your trip.
However, with bigger items where the function is more important, like BCDs, regs, and fins, buyers should really understand how they dive before taking the plunge and spending.
Different brands and models are designed for specific purposes and dive techniques.
If you’re not informed, it’s easy to make a bad purchase on equipment that will either not grow and scale with your diving, or will not last long with regular use.
The second-hand market for dive gear is huge, and most of the time, people are selling old gear to upgrade to better gear that will better serve how they dive.
In the interest of not creating any more waste than we need to, I believe that being better informed about dive gear will allow divers to make a purchase once with good gear that will last you your entire diving life.
More courses?
What about spending on taking more courses and increasing your dive knowledge?
Certain courses will teach you to be more comfortable in the water, and increase your dive skills.
I believe strongly that improving this has a positive effect on all your future dives.
Once you are truly comfortable and can manage your position in the water well, then all dives you do will be more enjoyable dives.
Less fear, less confusion about what to do, and ultimately, more enjoyment!
I firmly believe that getting to this point in your diving is the first thing you should invest in, as this has the biggest benefits to your diving.
Develop a passion for learning. If you do, you will never cease to grow.
– Anthony J. D’Angelo
I do think that gaining more knowledge through courses and experiences make one a better diver.
It also provides a path to understanding yourself and dive gear better too, leading to better and more informed choices about the kinds of gear that you want.
Make an investment in yourself today!
The two diving skill sets every passionate diver should consider
This post about skill sets is for serious divers who are truly passionate about diving all that this world has to offer, every ocean, every lake, every river. If that’s not you, then read no further!
The world is your oyster!
To me, any body of water is diveable given the right skills and logistics, it’s just a matter of whether it’s worth your time or curiosity.
My endless curiosity has always made me wonder what’s just a little deeper, just around the corner, underneath the surface.
Over time, I’ve built up a set of skills that I think truly allows me to look at any body of water on earth and think seriously about diving it.
All the time in the world
The first limitation in diving is one of time.
No decompression time limits and gas volumes limit most divers to about an hour on each recreational dive.
However, with technical diving, these limitations are made irrelevant with the appropriate logistics and skills.
In a technical diving course, you’ll learn how to manage different gas mixes, allowing for deeper dives and extensions of bottom time.
You would also learn how to calculate the decompression time and gas necessary to accomplish this.
Once you have the ability to dive with multiple tanks, then gas volumes also become irrelevant.
It just comes down to how many tanks you can carry or stage during your dive. It becomes a question of logistics.
Technical diving isn’t only about depth, but rather about decompression.
This can be calculated for a 2-hour dive at 25m, or a 1-hour dive at 75m.
Either way, doing a technical diving course allows you to go past recreational depths and time limits, whilst ensuring that you have the knowledge to plan enough bottom gas and deco gas to complete the dive.
It’s only cold in space
After getting technical diving skills, the next limitation most people face is the temperature.
Extended duration dives tend to suck the warmth from you, even in 28C water.
Warm water diving is actually limited to only a few degrees of latitude north and south of the Equator, and only tens of meters below the surface.
Once past the Tropic of Cancer and Capricorn, and you’re definitely in cold water country.
This leaves large areas of water that you’ll definitely need a drysuit to dive in.
Why limit yourself to Earth’s wonders that are only in warmer locales?
What about diving between continental plates in Iceland, or the wrecks of the North Sea?
So, the next most important skill set is learning how to dive with a drysuit.
This does take some time to get used to, as managing thick undergarments is no walk in the park.
But once you do, then all the wonders of the northern and southern latitudes will open themselves up to you, as well as longer dives in warmer waters.
Get wet anywhere!
With these two skillsets, I truly believe it enables divers to dive anywhere in the world you might want to.
Overcoming depth, time and temperature limits are not easy and will take some time to accomplish.
But just imagine knowing you can dive anywhere in the world. What a rush!
Bonus skill – getting in over your head
As a bonus, here’s the third set of skills that I think a true explorer should learn – cave diving, the last frontier.
I personally learned cave diving not because of the caves, but rather for the skills and knowledge of how to do dives in overhead environments.
These skills come in very handy when diving in wrecks, sea caves, or any kind of environment where you don’t have a direct ascent to the surface.
The true skill here is in learning how to better plan and manage your gas supply to guarantee that you and your teammates can safely ascend to the surface.
Another important skill set that cave diving teaches you is line management.
This is very useful in any survey or mapping exercise and keeps you on your toes as far as navigation is concerned.
Now, get out there and dive!
And there you have it, my three picks for the skill sets that you should consider to be a limitless diver!
When should I use a reef hook?
Umm, how about never?
Reef hooks… Such a pet peeve of mine…
It’s hard to agree with the general idea of reef hooks in the first place if you are concerned about the health of a reef, but some people swear by it!
How strong the current is, is the wrong question
Any sign of a strong current and divers start to bring out their reef hooks. Sigh…
I think that’s the wrong question though, not all current is strong enough that you need to hook onto a reef.
Where are you going, is the correct question
It’s more important to have an idea of why you are staying in place and not drifting with the current.
Some sites, like shark watching or manta cleaning stations, require you to stay in one position while you’re watching the show, so that you don’t drift forward and interrupt the animals.
However, I think that’s putting a band-aid on the symptom and not solving the real problem of why people can’t hold their position in the water.
Is it any wonder that Makassar Reef in Komodo (mantas) and Monad Shoal near Malapascua (thresher sharks) are full of coral rubble, and there’s barely a reef left?
Kick you must, or drift you shall
In places like these, I’ve found that the current is never strong enough that you can’t really kick against it.
If the current was really that strong, the animals wouldn’t be able to stop and hover at the cleaning stations either.
Learning to kick efficiently and maintaining a streamlined trim position is the correct solution.
Rather than relying on tools like reef hooks and pointers to hold your position.
Patience you must have, my young padawan
As divers, we should be patient when at these cleaning stations.
Observe what we came to observe, and leave when the time is right.
After all, how long do you really need to see a manta be cleaned?
Be like the water, and flow
In certain cases, sure, the current can be stronger than you can handle.
In those situations, I would recommend just putting a finger down on a rock or the sand.
It’s much less intrusive and damaging than a piece of metal that doesn’t have any feelings.
You’ve no idea how many times I’ve seen a reef hook dragging through a reef like a plow through wet mud.
I’ve even seen a metal pointer get broken in half because it was stabbed hard on a rock.
I shudder to think how many other corals died along the way.
Once it’s time to go, then be like the water, and flow.
Drift on, my friend…
The Path to Conservation
Speech on Reef Building projects by Livingseas at the ADEX 2017 Scuba360 Business Forum
A speech was given by Leon Boey to attendees of the Scuba360 Business Forum organized by the Blue Ocean Network at ADEX 2017 (7th April 2017).
He talks about the reef building projects Livingseas Asia has done previously.
He also highlights the current state of dive education and how it relates to marine conservation, finishing off with the things that dive operators and instructors can do to improve.
*Some images from the internet used without permission! Sorry about that!
Should I set up my own gear or trust the resort to do it for me?
Sadly, the current state of the South East Asian dive industry has devolved into operators who pander to their divers every need. Setting up equipment before the dives, changing tanks between dives, and even putting on fins for their customers.
Some divers have come to expect this level of ‘service’ and being spoilt with this lazy way of diving, have forgotten completely how to set their gear up themselves.
I am personally against this, and will not allow it in the operations that we have. It’s not that we can’t do it, but a matter of principle.
Who’s really responsible for your safety?
If divers can’t take personal responsibility for their own safety, then who is really at fault when an incident occurs?
The scuba equipment that we use is critical to keeping us alive underwater. If we don’t even understand how it works, then if and when something does happen underwater, does that diver know how to react and how to deal with that situation?
Should we be faulting the operations at which these incidents occur?
Or should we be faulting their Open Water instructors for not training these divers well?
Or is it the diver, who gets complacent and fails to check their equipment prior to getting in the water?
The practice of signing liability forms and waiver forms before any dive doesn’t negate the responsibility that operators have in keeping divers safe.
However, when we continue to produce divers who can’t even remember how to set up their gear, who is really at fault?
Blame, blame, everywhere blame
This is a chicken and egg situation, and I’m afraid passing the blame from one party to another is not going to change anything.
Ultimately, individual divers should and must have responsibility for their own safety.
Dive operators are there to provide the logistics for diving, and to provide a safety briefing of the common local conditions found at that location.
Divers should take primary responsibility for their own safety, and not rely entirely on a dive guide or Divemaster.
If a dive is risky, or uncertain, divers should not be afraid to speak up and ask questions, rather than just trust that everything is under control and follow blindly.
It’s not just about setting up equipment, is it?
I know this question is about equipment setup, and maybe some people will think that it’s not a big deal, but to be honest, I think it’s not just about equipment setup. This leads to other skills and knowledge that most divers take for granted.
Personally, I do think that this is symptomatic of a larger problem in the diving industry.
As individual divers, always look to get better training, even if you think you already have the relevant certification, as no two dives are ever the same.
We never know what Mother Nature is ready to serve up to us, so all we can do is to be as prepared as we can be.
How is the GUE Fundamentals course different from the PADI Advanced course?
The difference between the Fundamentals course and the Advanced course is really about the curriculum and comprehensiveness of the courses.
The Advanced course offers the new diver a chance to experience 5 other types of diving environments and covers those in a relatively quick format.
The Fundamentals course instead focuses on an individual and team’s dive skills, in order to manage these new environments effectively.
Diving and Driving, an analogy that keeps on going
The Open Water course is like the basic driving course that everybody does in order to get a driving license. It covers basic techniques, such as accelerating smoothly (propulsion kicks), parking (hovering), braking (ascending smoothly to the surface) and signaling (communication).
The Advanced course would be like getting experience driving on real roads, in real conditions. For example, driving at night (night dives), at high speed on expressways (drift dives), tight car parking spaces (peak performance buoyancy), and trying to navigate while driving in another country (navigation dives).
The Fundamentals course would be more like a defensive driving course, where you’d learn how to minimize your risk (awareness and teamwork), perform pre-trip inspections (gas management, dive planning, decompression management), and handling skids, accidents, and hazards (emergency drills).
Investing in yourself is never a bad decision
While the Fundamentals course and the PADI OW and AOW are different in terms of how they approach diver training, both are absolutely necessary for any serious diver’s training log.
Only after the basics are learned, can a higher level of skill be developed.
Personally, I would always recommend investing in yourself by taking the Fundamentals course, as it takes a more detailed and focused instruction in order to attain a higher level of skill.
I do believe that both types of courses serve their purpose well, but if you truly want to be a serious diver, then the Fundamentals course is the best place to get started.
Do GUE people only dive with other GUE people?
A lot of GUE divers, upon getting certified, will want to plan a trip with other GUE divers and go diving. Whilst diving more is always a good thing, what happens when GUE divers only want to dive with other GUE divers?
The Natural Attrition rate of GUE Divers
For me, this situation is not unsurprising. Who wouldn’t want to dive with a team that has the same training, protocols and thinking as you? Why wouldn’t you want to dive with someone whom you know has your back, and can keep you safe? This is in contrast to the ‘instabuddy’, who first meets you on the boat before the dive. You have no idea the level or experience that this person has, and no way of knowing what he’s like underwater. Generally, this doesn’t inspire confidence…
If we all think that way, then what next?
However, I don’t think this is good for the industry and for GUE in general. Firstly, there’s an impression that GUE divers are elitist, making them seem unfriendly and uptight when it comes to dive parameters. Keeping to oneself and not interacting with other divers definitely doesn’t help that impression, but this sticks even though some GUE divers are well meaning and not elitist by nature.
I say help if you can!
Secondly, I feel that as more skilled divers, we have a moral obligation to help and assist others. After all, can we stand by while the environment and other divers get injured and do nothing to teach and educate them about a better way of doing things?
Most diving incidents and environmental damage are entirely preventable, through better training and an increased awareness. By seeing GUE divers lead by example, my hope is that this thinking slowly permeates through the industry, regardless of agency or affiliation. Our greatest obligation is ultimately to the environment that we’ve all grown to love as divers.
So get out there and let other divers have the benefit of your presence in the water! Let them have a safer dive, just by being there. Wouldn’t you want to do this for all your friends who dive?
Let’s lead by example!
Look Ma, no hands, knees or fins!
Swimmers who are new to diving tend to have a bad habit of using their hands to swim.
Tender hands tend to get cut on sharp coral, especially if divers are unaware of their position in the water.
Knees and fins are also commonly seen on reefs, kicking up silt and breaking delicate coral.
Getting your hands and legs under control is one of the first things new divers should concentrate on.
Get streamlined and start to look like a real diver!