Scuba Tech Diving Centre: Last video of 2014

Finding your Path- Underwater Navigation in Scuba Diving

So, last week we started a blog series with regards to underwater navigation. Essentially, the concern is that we are training Scuba Divers to go Scuba Diving with a similarly qualified diver but, with the very limited Navigational Skills training on the initial training course, can we really say we have given them the tools they need to dive without a guide!

Now we will start to look at Navigation techniques that divers (of all level) can employ to find their way around a dive site, starting with the most common tool... Underwater Compass!

Underwater Compass

An Underwater Compass is usually liquid filled and the important elements you need to know about include; the Bezel, the Lubber Line, and the Card, which has graduated degree markings and the North Arrow.

Although it appears that the card moves, it doesn't. This is why the North Marking will always point North. The Compass housing actually moves around the card.

How do we Set a Heading

We like the Suunto SK-7 model, as it is very easy to use, so the instructions below are for this model. It is an indirect reading compass, which means it has degree graduation markings arranged clockwise on the Bezel, with 0 degrees (North) coinciding with the Index Marks. The card itself will show 180 at the top of the North needle... hence indirect!!

To use the compass, a diver simply turns the Bezel so that the direction heading we want to take sits at the top of the Lubber Line (which shows our direction of travel). You would then turn yourself with the compass so the magnetic needle sits between the index marks again and the Lubber Line remains aligned with the centre of your body.

So, if you want to take a 30 degree heading, turn the Bezel so 30 sits at the top of the Lubber Line (furthest away from you). Then turn yourself and the compass together until the North needle on the card sits between the index marks.

If that all sounds too complicated to you, you are probably over thinking it. The biggest problem I find with students learning to use a compass is that using it is simpler than they think. So, even though we spend ages practising on land before getting in, add water and they think they must be doing it wrong because it is too simple!

For a reciprocal heading, turn the bezel 180 degrees to head back the way you came.

To Navigate a square, the bezel turns 90 degrees (add or subtract depending on whether you want to turn left or right) while for triangles make 120 degree changes.




Things are even easier now with the advent of digital compasses that many modern computers
include. The newest of which is the new Shearwater Petrel 2.

It doesn't get much easier than this!

Some tips for using a compass for navigation on your dives

• Trust your compass. It is more likely that you are wrong than it is
• Hold the compass level 
• Be prepared to navigate around obstacles and account for currents etc
• Don't forget other essential skills such as buoyancy and air consumption. It's very easy to get transfixed by the compass to the detriment of all else.
• Practice with it so you are confident

A very handy tool to use but not the be-all and end-all of navigation, especially in clearer waters. Still, it is essential all divers know how to use a compass to find their route.

Finding your path underwater-Navigation for scuba divers

Diver training can vary enormously depending on where you train, who your instructor is and what they believe are the important skills for you to master.

Underwater Navigation is taught in the PADI Open Water Course but it is only really "touched on" and not explored in detail. Divers must navigate a straight line on the surface and then a reciprocal heading underwater. Ask divers if they know what a Bezel is and the majority will look back at you with a blank expression.

And yet... we are telling these divers that they are now certified to go Scuba Diving with a similarly
qualified diver. Have we really given them the tools they need to dive without a guide?

Over this series of blogs, we will look at Navigation techniques that divers (of all level) can employ to find their way around a dive site.

But first...

Why is Navigation an important skill to master?

When we dive, we like to go and see the points of interest. This could be wrecks, reefs, caves, certain flora or fauna or anything that strikes your interest, really.

Without navigational skills, we would be just swimming aimlessly, unable to find said attractions. On land we use our GPS or Tom Toms, don't we? These do not work so well underwater, so we use other means but the basic need is still there. We need navigational skills to find our route.

If we know where we are going on a dive, we can conserve breathing gas because we can find our way directly to the attractions, rather than wasting air going in the wrong direction. This will then give us more time to enjoy what we went down there to see.

For the same reasons, we can save on precious minutes eating into our No Decompression Limits.

Avoiding Long Surface Swims  is another benefit of being able to navigate underwater. It is a lot more tiring (and boring) swimming on the surface than gliding underwater, so if you have the skills to navigate to and from the attraction underwater, you should have a lot more fun!

Divers that know where they are going tend to experience Less Anxiety and Confusion, which is always a benefit when scuba diving. We have enough to deal with underwater without unnecessary stress in the mix. Read more about the stress spiral here.

So, navigation is a very important skill that we should learn and practice often. 

Don't get lost, check back next week when we will start to look at Navigational Techniques you can employ on your dives.

We will point you in the right direction!

Dive Presents for Scuba Divers

When it comes to Christmas presents, we aren't hard to buy for, we the Scuba Divers of this world.

Anything that helps us get wet, stay warm and dry whilst getting wet, lights up dark murky holes, is shiny or can be classified under the terms gadgets and toys will surely be a winner wherever a Diver is concerned.

So, here is a Christmas offer from Halcyon Dive Systems to make you feel Festive this winter. This is the Double Down Christmas 2014 Bonanza.

The offer looks something like this...

Buy a Halcyon Infinity Single Tank Wing System for €895 (£715) and get an Evolve Twinset Wing for just €100 (£80).

The Halcyon Infinity System is the ultimate in luxury for the special diver in your life (or even if you want to treat yourself!). It has all the durability and reliability that divers worldwide have come to expect from Halcyon products and incorporates the opulence of the Deluxe Comfort pads for back and shoulders all combined with the Halcyon Cinch system for easy fit adjustments.

Of course, the system has the basics; wing, aluminium or steel backplate, harness and Single tank adaptor.

Use the Backplate with the Single tank wing or the Twinset wing and you are all set up for any kind of diving you want to do... all for less than €1,000.

For more information, just get in touch with us at Scuba Tech Diving Centre

Moray-ly diving along at Cape Greko, Cyprus

SCUBA DIVING PROTARAS:



Just for fun Shelley and John went out for a bimble at Cape Greko. So many Moray Eels, we decided to call the video "Moray-ly Bobbing Along".

Do you want to come and Swim the Ocean Blue with Scuba-Tech Divers? Get in touch www.scubatechdivers.com

Don't Drink and Dive

With the festive season fast approaching, we all find ourselves with lots of nights out and parties to attend to celebrate. Be it with friends, family or work, it is easy to find yourself over doing it with the alcoholic beverages but if we are diving during this season, how can this impact our health?

Obviously, we all know the risks of drinking too much and most of us wouldn't even consider having an alcoholic drink before we go Scuba Diving but just like driving the morning after a big night out, can alcohol still affect us while we dive?

The answer is a big resounding YES!!

It takes time for our bodies to metabolise alcohol in our systems and there are no hard and fast rules. Like diving and Nitrogen off-gasing, everyone is different and everybody's metabolic rate can vary. 

Narcosis and Alcohol

Tests have shown that a diver's ability to complete skills on Scuba is dramatically compromised with a Blood Alcohol Concentration of just 0.04% which is less than the legal limit for driving a car and, after a late night drinking, can easily be the level left in your body the next morning.

Add this impairment to that which we already feel as divers through Nitrogen Narcosis and you are asking for trouble, especially if old Murphy pops his head up....

Energy Zapping

Which leads us quite nicely onto our next problem with drinking the night before diving. Alcohol Drains Energy by impeding the liver from producing the body's primary energy source, Glucose. This can leave you feeling tired and lethargic.

If Murphy does show up on your dive, you want to have a bit of Energy in the bank to be able to deal with the unexpected. A lack of Energy can leave you incapable of dealing with it safely and expediently. 

Chilling

Feeling chilly? Have a wee dram of brandy to warm your cockles, right?

Wrong!

Alcohol actually works to dilate the blood vessels close to the skin, allowing blood to flow closer to the surface, which makes you feel warmer but with blood flowing away from the core and so close to the surface, you lose heat and chill faster.

Add this to the fact that we lose heat 25 times faster in the water anyway and those drinks are putting you at increased risk of Hypothermia

Dehydration

We have touched on Dehydration and Diving in previous articles and discussed all the risks that entails. In brief alcohol affects the kidneys, which is going to lead to a loss of body fluids and when you combine this with the dehydrating effect scuba diving inherently causes, we greatly increase the risk of DCI.

So, the take-away from this blog is not kebab and cheesy chips or to put a damper on your Christmas festivities. This is just a reminder that if you are scuba diving, take it easy the night before and after your dives.

You don't have to abstain completely but moderate your alcohol consumption and maybe switch to soft drinks after 11pm to give your body a good 8 hours, at least, to metabolise the alcohol to an acceptable level.

Above all else...Dive Safe!

Long Hose Diving from the beginning.

Currently teaching a TDI Advanced Nitrox Course to one of our Divemasters here at Scuba Tech Diving Centre and we found ourselves having lunch in the sunshine discussing the merits of using the long hose configuration.

Now, the long hose Hogarthian configuration is used in all technical Diving and Sidemount diving standard equipment set up and yet, for recreational scuba divers and beginners, we still start off using the standard 75cm regulator hose/ 90cm alternate configuration.

                     

What is the Hogarthian Long Hose set-up all about?

The Hogarthian is actually named after its creator, William (Bob) Hogarth Maine.

Bob was a cave diver that developed the Hogarthian Set up as a means to more efficient dive practices, keeping things simple and ultimately... safer!

The Hogarthian regulator set-up comprises a second stage on a short hose (60-75cm usually depending on the size of the diver using it) which is hung from a bungee around the neck.

The long hose is usually 1.5 to 2.1 metres in length and comes under the right arm, up over the left shoulder and around the back of the head to the mouth in a big circle. This is your primary regulator but also, the one you would donate in an Out of Air emergency.

Why is Hogarthian Long Hose configuration better?

You always have an alternate air source around your neck, so if you were to lose your primary regulator for any reason, you have something easily accessible to breathe while you relocate it. This offers you the life saving gift of time to sort the problem.

In Out of Air situations, you donate your primary regulator and switch to your back up around your neck, which has the advantage of giving the out of air diver, what they can see is a working regulator. In a  panic situation, it is not unheard of for divers to grab the regulator out of your mouth. With this system, all you need to do is dip your head forward to free the long hose and switch to the secondary regulator around your neck.

An added advantage is the long hose offers a bit of room for manoeuvre and it is workable even if you have your emergency inside a wreck or other overhead environment.

You also avoid that pesky dangling alternate air source that gets loose regardless of how well you clip it up to get a cleaner, tidier, more streamlined set-up.

Why don't we teach this from the start?

This brings us back to the question of why we wait for technical diver training before most agencies implement this system of diving?

On the very first training dive we ask our trainees to "lose" their regulators behind their backs and control their breathing while they relocate them. Why not KISS? 

Keep It Simple, Stupid!

If they lose the reg, swap onto another working regulator so they have time to solve the problem. In a hostile environment, we need all the help and simplicity we can get, so it makes sense... doesn't it?