Browsing Category Recreational
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!
Why does my finger get cut on bolt snaps?
Almost everyone who’s had any experience doing a course where drills and bolt snaps are involved ends up with fingers and thumbs cut up like in the photo above.
Why does this happen, and how can we prevent it?
Rushing is never a good thing
Bolt snaps, while great for attaching to dive gear, is terrible on fingers when used incorrectly.
The skin on our fingers gets softer when diving for a while.
This delicate skin is easily scratched and torn when rubbed on a sharp surface.
A badly torn up thumb from using a bolt snap incorrectly.
Be careful where you put those fingers!
Gloves aren’t really the answer, as always, I’m more in favor of dealing with the cause of the problem, rather than fixing a symptom.
The proper method for managing bolt snaps then is to place the side of your finger on the trigger, and not press your flesh into the sharp edges of the slot.
The proper way to hold a bolt snap open.
The sharp bit of a bolt snap is the slot that holds the spring of the trigger, not the trigger itself.
By placing your finger further out, you’ll reduce the risk of the two sharp edges slicing your skin.
Slow is smooth, smooth is fast
Get a good finger position on the trigger, then position the gate next to the D-ring before applying pressure. The bolt snap should slip right into the D-ring at this point.
Too often, I see divers trying to ‘catch’ the D-ring with the gate while holding it open.
Or they would apply too much pressure on the trigger because they are stressed out and trying to get the drill done quickly.
As with anything in life, rushing is never a good thing.
Slow is smooth, smooth is fast!
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!
How do I tie a good knot?
Attaching bolt snaps to dive gear like SPG hoses, regulators and backup lights make them easier to stow.
Now a common question I get is: So how should I tie a long lasting knot?
We’ve addressed the different types of knots in a previous article, so read this if you would like to find out more about attachment options.
In this article, I’m going to show you how to get a good solid knot tied, so that it lasts (almost) as long as your gear.
A lot of other articles and videos also show how to tie a knot, but I’d like to highlight some of the more important things that I look out for to make sure the knot stays tied over a long period of time.
At the end of the article, I’ll also show the common errors that might cause a knot to fail.
Line choice
Traditionally, most people would use the same line found on their spools to tie their knots.
I’m not a great fan of this, for 2 reasons.
Firstly, it shortens your spool, resulting in an unknown length of line left on the spool.
This is a problem especially if you have a lot of things to tie. I would never recommend going diving without knowing the length of line you have on your spool.
Secondly, and more importantly, I don’t find the braiding on that line appropriate. It’s much too heavy.
A tighter and thinner braid on the line doesn’t stretch as much when wet, creating a more secure knot that doesn’t slip.
Image of a thinly braided line on the left and a heavy braided line on the right
Loop around the connection point and bolt eye
I normally go for 3 or 4 loops around the connection point and the eye of the bolt snap.
For long hoses and SPG hoses, I tend to do 4, but for heavier or other more dynamic knots, I would use more, sometimes up to the width of the bolt snap eye.
Looping the line through the eye of the bolt snap
Cross over and pull tight under the bolt snap
After getting the loops nice, neat and tight, I would bring both ends of the line to the same side of the bolt snap.
Getting the line to the same side of the bolt snap
Then cross both ends of the line and pull them tight, pulling them under the eye of the bolt snap.
Crossing the line and pulling it tight
Pulling the line under the eye of the bolt snap
Ensure that the line is tight around the original loops, making sure that the outer loop is cinching the original loops tight together.
Right over left, left over right
A nice solid knot requires a good tie, and the best one for this situation is the square knot.
Right over left and left over right, that’s a simple phrase I remember to get this correct.
It’s a good knot because the lines tighten on themselves, and it forms a nice flat knot that doesn’t stick out and get abraded.
Tying a square knot
The final square knot
Cut and burn one end at a time
Once the knot is nice and tight, it’s time to seal the ends by cutting and burning off the tips of the nylon line.
The trick here is to cut and burn only one side at a time.
Cut the line as close to the knot as you can, about 1 or 2mm away from the knot.
Only cut one end of the line first, do not cut both sides!
Use a lighter and place it perpendicular to the line, using the heat from the blue part of the flame to melt the line onto the knot itself.
Use a lighter to burn the tip of the line and melt them onto the knot
The melted line on the knot
It’s important to make sure that the excess line is melted into the side of the knot.
This is critical so that the line doesn’t pull out when you cut the other side of the line.
The final knot in all its melted glory
Make it last forever!
I’ve tied knots that have lasted 5 or 6 years with this method, so by following this guide, I’m sure you’ll be able to get a good knot going. Good luck!
Common errors to look out for
Wrong knot
It’s very common to tie a granny knot by repeating the same half knot in the second half of the square knot.
This is not a good knot and tends to slip.
It also tends to stick out, making it prone to abrasion.
An old timer granny knot
Not doing one side at a time
The problem with this is that pulling on one side of the knot will cause the other end to slip out if you’re not careful.
In the least, this will cause the knot to slip and open up a little bit, making it looser.
Cutting both ends of the line before burning them results in a loose knot
Not burning the line into the knot
Burning the tips of the line away from the knot allows the line to slip back into the knot, loosening the knot over time.
Burning the tip of the line away from the knot results in pull back and loosening of the knot
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 use a 5 foot or 7 foot long hose?
There are two schools of thought regarding the length of a long hose.
5 or 7 feet (1.5 m or 2 m)?
Let’s explore where they came from and the rationale behind each of them.
7 feet – longer than the average human
The 7-foot hose came from the cave diving environment.
Divers would need to share gas, but sometimes having to go through a restriction swimming in single file.
This made the regular short hose unusable, as you wouldn’t be able to share gas with someone in front or behind you.
The 7-foot hose was used so that divers could have the out of gas diver in front of the donor in single file and still have enough hose to be comfortable (unless you were sharing gas with an 8-foot tall giant…).
Ocean divers then discovered that a longer hose would help in keeping the divers further apart, allowing for better maneuverability and comfort.
However, some people thought that the 7-foot hose was too long because you would never really be sharing in single file in an open water environment.
A 5-foot hose was then adopted as a compromise to having a longer hose to manage while sharing.
5 feet – still a long hose but is it too short?
Personally, I would always use a 7-foot hose, but not for the reasons of sharing ironically.
The longer hose is definitely harder to manage when you’re learning it, but overall, I think it loops better and stows away better into the waist belt or behind a canister light.
This holds the hose in position during the dive, and if managed properly, the hose will stay in that location and not move around.
The 5-foot hose would be trapped under the right armpit when used by a larger diver.
In some cases (8-foot giants especially), this can get uncomfortable to the point of not having enough hose length to turn your head to look left.
Smaller sized divers would not have this problem.
However, as the hose is not secured, it will float and move around behind the arm and potentially above the head.
This may create problems when diving doubles, as the hose extending from the second stage tends to get looped around the isolator manifold or right regulator and knob.
Once there, a sharp turn to the left can actually pull the second stage out of the mouth!
7 feet – a Goldilocks length
For these reasons, I personally would always recommend using a 7-foot hose.
It’s long enough for everyone to be able to tuck it securely under the canister light, or into the waistband.
If your waistband is tight enough, then the hose should not pop out on its own accord and float around.
Having stuff in places where they are secure is a big thing for me, as is keeping things nice and neat.
I really hate it when equipment comes loose and causes problems during a dive.
Equipment should be there to support me, not cause additional issues!
Are diving doubles and sidemount the same thing?
In terms of the number of tanks you might carry, sure, doubles and sidemount appear similar.
However, sidemount and backmount doubles differ in one crucial area – the isolator manifold!
Why would you ever need more than one tank?
Now, let’s start from first principles.
What are the reasons for carrying more than one tank in the first place?
Some might argue that gas volume is the primary reason, however, redundancy is a more important and valid reason.
On a normal single tank (especially one with yoke valves), O-ring failures (tank neck, tank knob and yoke valve) are relatively common.
The next most common thing to fail in scuba gear would be the regulator setup, as there are many O-rings and hoses that can rupture and cause a catastrophic gas loss.
Single points of failure are dangerous when diving
With single tanks, a gas loss from an o-ring failure in the yoke valve or the regulator will result in an immediate out of gas situation.
In order to deal with this situation in deeper or more extreme dives where a direct ascent to the surface is impossible (a decompression obligation or an overhead environment), we would require a secondary gas supply so that we don’t go into an out-of-gas situation on a single failure.
Double your tanks, double your hoses, double your failures
A quick solution to this was to just carry another tank.
In the early days, people would just carry 2 tanks, with a full set of regulators on each, in essence, doubling up on the gas supply, but also doubling up on the failure points in the system.
However, what if halfway through the dive, you had one full tank and one nearly empty tank and a failure happened on the full tank?
This would leave you with a nearly empty tank, with no backup.
Clearly, this wasn’t an ideal solution.
What about connecting these tanks?
The best solution to this was connecting the tanks with an isolator manifold.
Two 300 bar scuba cylinders connected by an isolating manifold
Using this setup, we could have a single regulator failure but still have access to all of our gas supply.
The isolator is an important part of this setup because it would allow a diver to isolate an unfixable leak to just one tank.
This prevents an immediate out-of-gas situation because you would still have one regulator working.
Some might argue that the manifold itself presents a failure point, but in all my years of diving doubles, I’ve not seen a bad manifold failure happen in the water.
In most cases, if the manifold were to fail, it would fail during the filling or setup process.
So what about sidemount?
So where does this leave us in the discussion on sidemount vs backmount?
Sidemount was created because of a specific need to access ever smaller and tighter holes in cave exploration. Places where backmounted tanks would have limited access.
Diving sidemount in open water negates the benefits of carrying 2 tanks by reverting to the original idea of the independent doubles. This of course comes with the associated negatives mentioned above.
There are some benefits to diving sidemount that proponents argue on; that it’s easier to put on; easier logistically; better for the back, etc.
See my other article about diving sidemount in open water to get an idea of why I think that’s not so relevant.
However, when we come back to the main reasons of why we have multiple tanks, sidemount just doesn’t match backmount when it comes to redundancy.
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.