To Boldly Go… A bit deeper than the time before

Never Ever, Have I Ever…

Heard a student start a course saying that they want to dive deep. There are exceptions to this rule of course, but the majority start off with “I only want to go 10-15m, that’s enough for me”

That limit sticks, right up to the point that they go to whatever their target depth. where they decide that it was great and not really any different from a couple of meters, they also see there there is no “magic” line at 18m – which incidentally is only there because the pioneers chose 60″ as the entry level depth, had they been of the modern world, chances are 20m / 66″ would have been the limit.

So then it starts, the lure of the DEEP…

Anyone that’s sensible will progress their depth, with plenty of shallower dives in between. That way they bring up their comfort and skill level to the maximum depth hit previously before planning another PB dive. Most will also be progressing through the core courses at the same time, allowing each aspect of their diving to be complimentary – please don’t think as some do, that doing course after course after course is the best way. You have to get experience in there somewhere. If i had to put a number, then 15 dives as a buffer to early PB dives and 30 between courses. There is of course a limit to how deep people will go, this is a very personal thing and nobody should ever pressure, or feel pressured to break that personal limit. From experience, i would say that 100% of properly experienced divers will do 30m, this drops to about 50% for 40m, 10% for 50m and 2% 50m+ this rule will change slightly thought if you factor in helium use in either trimix or helitrox.

So, why go deep at all?

Well, locally speaking the diving is just… Better… I’m not saying that all shallow diving is rubbish, far from it, but there are many benefits to heading deeper. The main one is that as you go below 18-22 meters (depending on time of year) then you will lose most of the seaweed, which in the shallows, is hiding all the topography and life. As you pass this invisible line (actually to do with light penetration) you’ll start to see far more interesting life, soft corals, gorgonia, sponges and the incredibly pretty swathes of jewel anemones.

One thing that is almost always better in the deep, is the visibility. I think of vis in 2 ways, the actual distance that you can see and the clarity of the water. For me clarity is way more important than actual distance. You can bet that 99 times out of 100, clarity in the deep will be better than the shallow, especially in the summer months with the “bloom” in the water. One thing that does dwindle with depth though, is the light. But luckily there is a new-fangled device for fighting this – it’s called a torch.

If your into scalloping, then there is no doubt that the scallops are more dense in the deeper water, mostly as less people go that deep. There is a fine balance though, as the deeper depths mean much shorter dive times which in turn means that you catch less. Many people over the years have thought that depth would improve their catches, most soon discover that the execution of the dive also becomes more important as you go deeper. When it comes to scalloping, most stick to the mid range of 20-40m, anywhere outside of this range is likely to be hit and miss and we can’t have that in such a fierce competition…

Some say that competition has no place in diving, i couldn’t disagree more. Whether it be on number of scallops, size of fish, max depth, dive-time or gas remaining. There is absolutely nothing wrong with a bit of healthy competition between mates and even with yourself. Competition is in human nature, it’s what drives us as individuals and as a race to be better than we were yesterday. If it weren’t for this drive, we would most likely still be living in caves! Of course, the competition needs to be healthy, and it needs to be last on the long list of dive requirements – with safety being first. Maybe with our divers the battle is more in the open as we shout “SCORE” after every dive, but trust me it happens all over the world. Where you don’t see it, it just means that there is probably less to compete over – why do you think dive guides in the warmer climes have such low breathing rates?! Those that don’t want to compete in diving, probably can’t…

Another reason is “lust for rust”, anyone that likes to wreck dive will eventually decide to go that bit deeper. This is because whilst there are many wrecks in the shallows, most resemble a pile of “stuff” with seaweed growing out of it. For me, i like to be able to recognise what the wreck was in it’s previous life.

For wrecks less than 20m, you’re really limited to just the Forth. If you go up to 30 ish, then you can add the Cement wreck (30m) and the Ammo wreck (32m). A diver that pushes to the next step will gain access to a heap more: Mary Toovey (42), Figaro (45), Stella (46), Brighton (50), Niko (50), Duanna (50) Cairnside (52), M483* (52). Those that really show a passion and aptitude for the deep and go on to Trimix will open up the really special ones: Edirne (55), Bizon (58), Rouen (58), Jeanne Marie (58), St Malo (69) and many others.

*Arguably the best wreck dive in the channel islands – for more info and links to video, see the main website

In listing all these reasons, i’ve missed out one very important one – diving deep is immense fun. This is largely due to narcosis (more on this in a later blog). Well at least it is to some people, now i’m not saying that everyone needs to dive deep, people should do what they want. But if you like pushing yourself and you’re willing to accept the increased risk, why not go for it.

One last point i’d like to make, is that just because you can dive deep, you don’t have to. I know that it gets said of me that I only dive deep and yes, if i have the choice, then mostly i will pick deep over shallow. Of course, if i’m diving with someone, then i will dive to their limits and I do enjoy the occasional shore dive. If i didn’t then i wouldn’t do it especially not on my own (which i have been known to do in desperate dry times). Only last week I went into Havelet to dive with someone because they needed a buddy, instead of going scalloping and earning money.

What the naysayers miss though is that if you can dive deep, then you can dive shallow. A skill that doesn’t work the other way. Think of it this way, can a racing driver drive a normal car slowly, the answer is of course yes, but does being able to drive a normal car make you able to drive a racing car fast…

So go forth and embrace the narcosis!

You know it’s cold when…

You lose a team member after a couple, because the normally bearable suit leak is too much – “My bollocks are wet, i’m done”

It’s mid Feb and you’re pleased to get back in the water to warm up, which is normally an Autumn / Early Winter phenomenon

You do an extra couple of minutes deco, just to stay in the water longer and keep away from the sleet / rain / hail

While shucking, your hands go through the 4 stages: Ok – Cold – Numb – Painful

Also while shucking, you don’t speak a single word to each other

It’s 4 hours later and your feet and hands are still cold

It’s on your mind, so you write a blog about it!


I know, massive Big Girls Blouse (probably can’t say that these days), but damn i’ve got respect for those still diving in a wetsuit!


Rebreathers, first impressions from a buddy…

Now that there are a couple of new rebreather divers in Guernsey, it’s more than likely that you’ll hear some rebreather-speak this coming year. So I thought that i’d write a post about what they are, and what my first impressions are of being a buddy to someone diving with one.

Firstly, my only experience diving with one is a try-dive a few years ago with Mark Ellyatt in the south of England, whilst over there doing some SDI / TDI Instructor training. This consisted of a 10 min chat and then jumping into the shallows of a bay to swim about for an hour.

For those that don’t know, what we refer to as a “rebreather” is more accurately called a “Closed Circuit Rebreather”  or CCR for short. All CCR’s will have 6 common components, an Oxygen (02) cylinder, Diluent cylinder, scrubber, a head with various electronic monitoring systems, some counter lungs and a breathing loop.

The 02 cylinder is just that, a cylinder filled with oxygen.

The Diluent cylinder is filled with a gas compatible with the maximum depth of the dive. This would typically be air (21%) down to about 40m and trimix for depths beyond that.

The scrubber is essentially a canister filled with soda-lime, a chemical that reacts with C02, changing it chemically and effectively trapping it within the soda-lime itself.

The head comes in many different configurations, but all will contain a number of 02 cells like you get in a nitrox analyser. These cells will then be read by a CPU and the information displayed on a screen for the diver to see. Many units also have a built in controller that runs the unit based on that information.

The counter lungs offer storage capacity for gas before and after exhalation, they are flexible and somewhat collapse when you breathe in and inflate when you breathe out.

The breathing loop is a set of hoses that run from the scrubber, to the mouthpiece via the counterlungs.

So, how does it work…

The diver breathes in, taking in gas from the 02 rich inhale counterlung, 02 is transferred in the divers’ lungs to the blood stream. In turn the body gives out C02 and water vapour. This low 02 / high C02 mix is then exhaled into the  exhale counterlung, prevented from going anywhere else by 1-way valves in the breathing loop. On the next breath, this gas with then be pushed into the scrubber. As it passes through the scrubber the C02, water vapour and soda-lime cause a chemical reaction which traps the C02. The gas that reaches the top of the scrubber will then hopefully be low 02 and no C02.

This low 02 gas will then pass over the 02 analyser cells, this information will be sent to the diver and controller. The diver or controller will then make a decision as to whether the 02 level is sufficient. If it’s not then either the controller will open a solenoid valve or the diver will press a button to allow more 02 in to the system to bring it back up to the correct level. The gas then continues it’s path back into the inhale counterlung and on to the divers’ lungs again.

Where does the Diluent come in?

As the diver descends 2 things occur. The volume of the gas in the system will decrease as the water pressure (depth) increases, meaning that there wouldn’t be enough to breathe. Secondly, the pressure (quantity) of 02 will increase. If 02 was added to the loop to make up for the lost volume, the pressure of 02 would quickly reach dangerous levels. So to stop this happening, a low 02 mix must be added to make up the volume. In the case of gas loss from the loop, adding diluent may drop the 02 pressure, in which case the diver or controller will add more 02 to maintain the mix to the required level.

As the diver ascends, the opposite happens. The volume in the loop increases and the pressure of 02 drops. To counteract this, the diver has to “lose” some gas from the loop via a valve, or exhale through their nose so that the gas escapes. The diver or controller will simultaneously be adding 02 to maintain the mix to the required level.

In short, the 02 cylinder raises the pressure (quantity) of 02 in the loop, whilst the Diluent lowers the pressure (quantity) of 02 and raises the volume of gas in the loop.


As a buddy, you need to have a fair understanding of all this stuff in case you need to help a CCR diver. You also need to make sure that you keep a close eye on them both figuratively and literally. Because with no bubbles there is less to see, especially on descent / ascent, and no noise either.

As a non CCR diver, you’ll likely always be the person to end the dive as the CCR has several hours of endurance per fill. Also, due to the constant pressure (quantity) of 02 provided, they’ll have a longer NDL or less decompression than you will on normal scuba gear.

You may be reading this and think “What’s the downside” well, there are a few.

Firstly, you have the expense of the unit originally, plus high service and maintenance costs. This can be offset somewhat if you are saving on Helium costs by doing lots of deep diving, but it does have to be a lot of diving!

Secondly, the CCR diver has to pay attention, like ALL the time. It’s not something you can check every now and again. If you don’t check it enough, it’s very likely that it’s going to ruin your day! This also applies to pre-dive checks, post-dive maintenance and everything else to do with the CCR, if you scrimp on either time, focus or cash it’s not going to end well.

For me, this actually detracted from the enjoyment of diving somewhat, having to pay so much attention to the CCR and less to the fishes.

But, when all is said and done, CCR?   YES, sign me up…



Drysuit? Pah, just use some bin-sacks and sticky tape…

There’s no doubt that if you want to be a “serious” or year-round diver in Guernsey you have 2 options. Either you grow a massive pair of balls (or the female equivalent) and dive in a wetsuit, or you get a drysuit.

I should point out that by “serious” i mean someone that does multiple dives on one day, or someone that does long or deep dives.

Now, for those that don’t know, there are 4 main types of what is called Exposure protection.

The first is a reef suit or rash vest, this is a very thin garment that protects the user from scrapes, and offers some protection against sunburn. Typically these are worn in very warm places and offer little or no thermal protection.

Next is the bog-standard wetsuit. These are made from neoprene which is gas bubbles in a rubberish material. Wetsuits work by trapping a little water which  allows your body to heat it. Once the water has warmed the water it is effectively trapped and works as part of the insulation. Neoprene varies in thickness from 0.5mm to 7mm. A typical suit used in Guernsey would be a 2 piece 7mm suit resulting in 14mm of insulation on the torso.

Third, we have the Semi-dry. These are basically a wetsuit with much better seals and typically a dry zip. This means that water infiltration is minimal and very little gets in. We’ve seen this type of suit come in and go out of fashion over the last 25 years, currently they are in fashion so much that production of the standard 7mm wetsuit is non-existent. Personally i’m not convinced that the semi-dry is any better than a wetsuit. What i do know though is that they are more expensive to buy, require more care and are more likely to get damaged and need expensive repair.

Last, but by no means least is the drysuit. These come in many different styles and options, with the main one being the material, which is either neoprene or membrane. Neoprene suits are normally worn with minimal under clothes, with the suit itself providing good insulation. A membrane suit offers practically no insulation, so you need to wear an undersuit. One of the big benefits to using a membrane suit is that you can vary the type and thickness of the undersuit throughout the year according to the insulation needed.

A drysuit works by keeping all the water out with seals on the neck and wrists, with the boots usually fitted to the suit. The seals are made from either latex, neoprene or silicone – which has only been around for a short while. Because of these seals, the suit becomes an air-space which means that you need to equalize the pressure by adding air on the way down, and removing it on the way up. This is done with 2 valves, an inlet on the chest that feeds air from your cylinder to the suit and a dump valve on your left shoulder to allow excess air to escape. The modern dump valve is variable which allows the diver to set the pressure at which it opens. Back in the time when Noah had hull inspections, there was a type of dump called a cuff dump. A cuff dump is a very cheap valve that sits around the wrist, when you raise your arm and the sleeve fills with air, it dumps – great for waving on the surface.

That’s it, it’s really no more difficult than that!

Or maybe it is more difficult, what with all the courses available and the horror stories that you hear…

Fact, I’ve never issued any certification relating to drysuit use, there is just no need. Providing that the “student” has more dives than they can count on their fingers, then it’s never a problem. Like most things, some take to it quicker than others, but the difference is generally between 5 and 30 minutes!

So why all the horror stories?

Well, I think in the vast, vast majority of cases it comes down to one of 2 things. Either the person has not been told how to use the suit, or it’s the wrong suit for that person. In other words, they’ve borrowed a suit from a mate, or bought something 2nd hand on the cheap. They then get into the water and soon discover that it’s not as easy as it looks!

To follow this theory, lets have a look at the things that can go wrong with either type of suit.

With a wetsuit, very little. If you can get it on and breathe, then you’re good to go.  The suit will loosen slightly as it gets wet and compressed by the water pressure. The only real danger with a wetsuit is if the neck is really too tight it can compress the arteries in your neck, which fools your brain into slowing your heart which can lead to unconsciousness. If it’s too loose, then you get colder quicker and if it leaks it doesn’t matter because that’s what it’s supposed to do.

For a drysuit, there are a great many things that can go wrong.

If it’s too tight on the body it wont allow for the movement that you need and it could restrict your breathing. If it’s too loose, then it will hold too much air, this will mean that you need more lead to sink. That extra air can move about far too much and upset your trim and balance in the water. If all that excess air ends up in the feet then it can “blow” off your fins and make righting impossible which will lead to the inability to remove excess air and result in an uncontrolled ascent to the surface.

If the neck seal is too tight, it can compress your arteries and lead to unconsciousness. If it’s too loose, then it will leak. This results in massive loss of thermal insulation, buoyancy and in a bad case can make it impossible to exit the water in the normal way due to the weight, especially if the suit is too big.

If the wrist seals are too tight, they can affect the dexterity of your hands which will make tasks more difficult. If they are too loose, they will leak leading to the difficulties mentioned above.

If the boots are too tight, you can suffer cramps in your foot and calf, this can make it difficult to swim which in turn can render the diver helpless. If the boots are too big, then your fins can easily come off. When this happens, chances are you are heading, uncontrolled, to the surface. Maybe this leads to nothing more than a bit of embarrassment, or maybe you damage your ears and sinuses. Or perhaps it’s a very bad day and the fast ascent leads to a lung over-expansion injury, omitted decompression and “the bends”.

In the good old days, this sort of thing was very rare. This was because people would buy a drysuit and the training would be thrown in. There was no need to teach someone how to use a drysuit that wasn’t right for them because nobody was trying to get their “Drysuit badge” (watch out for blog on this later). Of course, there are some places that can have “school” drysuits, but these are only the very biggest of dive centers with 100’s of students in very cold places where drysuit is the only choice all year round. Remember, the suit needs to fit properly, with appropriate insulation, correct boot size and have seals of the right size. So the idea that somewhere can have a couple of school suits to “suit” everyone is just stupid!

So, the bottom line…

Unless you are happy to make a suit out of bin sacks and sticky tape, get a decent one. Not only will it be a joy to dive in, it will last for many years. The best in our opinion is Otter, they are the only make we use and actively supply.

Students – Get some experience first in a wetsuit to be sure that local diving is for you, then get a suit that fits and is right for the job. Next get someone that knows what they are doing – someone that actually uses one on a regular basis – to show you how to use it.

Instructors – Just stop it, you should know better, or maybe that’s the problem…


To Float, or Not To Float…

The neutral buoyancy debate

Recently, on a near daily basis I’ve been reading articles about how student divers should never kneel on the bottom. The authors say that this is to prepare them for “real” diving.

I want to share my thoughts…

First, let’s look at why the authors are writing these articles in the first place. Now unless they are small scale meant for their own students and divers then they WILL be doing it to try and get noticed. Usually this is an effort to become a well-known national or international instructor and travel for work. Or it’s because they are looking to become published in magazines ect. Obviously the more shocking the material the more likely they are to be noticed.

To the topic in hand. What is being said in all these writings, is that student divers should never be taught to kneel on the bottom. They then usually show a picture of a “typical” dive class with students kneeling on the bottom waiting to perform their skills, this is then backed up with another picture of some divers trashing a coral reef or silting up a cave – both bad things as every diver should know, but not really the same thing. Just because you have knelt on some sand or a pool bottom, it doesn’t mean you’re going to kick the hell out of the reef.

The thing is though, whilst it’s a great ideal to have every student perfectly floating neutrally buoyant. The fact is though, that it’s just not realistic in a Open water class. For us that dive in poor vis, there is no way that an instructor could maintain a safe level of control if all the students were off the bottom. ‘Cos lets face it, they are students and therefore learning!
Good buoyancy control is motor skill, a feeling if you will. Some people do pick it up easier than others, but for the vast majority it takes a little while. I would say, that in nearly 15 years of teaching only a handful of students have had good buoyancy right off the bat. Most do take around 10-15 dives to really get the hang of it.

The problem I think, is that there are too many instructors teaching the absolute bare minimum courses. Yes they are doing everything required, but what is actually required in the course syllabus isn’t that much. For instance every pool dive has “fun and skills practice”, while every open water dive has a “underwater tour” portion of the dive. Now these are quite vague, does 30 seconds count? I don’t think so, and will always give students 5-10 minutes “play time” at the beginning and end of every pool session and end each sea dive only when a comfort or air limit is reached, this usually means at least 45 mins dive time after skills have been performed.
Also, it’s become very common for instructors to push course after course after course, with absolutely no normal dives in-between. In fact, there are even some instructors with almost zero real dive experience.
One example, is people taking the Peak Performance Buoyancy Course (PPB). Now there are times when this would be valuable, for instance when taking on a new student that wasn’t taught properly in the first place. I think that there is absolutely no reason for people to immediately take the PPB course with the same instructor. The fact is that all agency standards state that buoyancy must be “mastered” before Open Water (or equivalent) certification. So in essence, the instructor is saying “I didn’t do my job properly, your buoyancy control needs work, so pay me more money to do something I should have done in the course that you have just paid me to teach you” – this is not on!!

Personally I always try and get a few extra dives in, either during or after the course, to make sure that the student has got to the proper level. Let’s be honest, nobody expects an amazing diver after the Open Water course, BUT an Open water diver should be competent and comfortable in the planning, execution and navigation as part of a similarly qualified buddy team in conditions similar to those in which they trained. In other words, 2 divers finish the course in the morning, they should be capable of going for an easy shore or boat dive in the afternoon…