Crab or fish - it's your choice!

THE AQUALUNG ENABLED MANKIND TO SWIM UNDER WATER - or did it? What if every human who has mastered the aqualung and thinks he or she now possesses the secret of swimming under water has been sadly deceived?
Brilliant invention though the aqualung was, one thing it did not do was help us swim under water. In fact the opposite seems to apply - scuba too often renders this skill unnecessary.
The younger me enjoyed escaping responsibility as much as the older me, but got away with it more often. Long summers idling on a Spanish beach could last that much longer when I was able to stretch my funds by spearfishing for my dinner.
It took no time at all to stab enough sardines for the pot, and this left me with time to step away from the harpoon and go play with the creatures that I had been hunting shortly before.
The skills I learned in stalking fish for food turned out to be equally useful when I was simply playing with them. Watching the way wrasse and grouper back-pedal with their dorsal and tail-fins taught me how to back-scull with my own fins, giving me an effective underwater reverse gear. Swimming close to the rocks and sand like a dogfish taught me to steer with my body without once scratching my belly on a barnacle.
Playing with the water as the wonderful supportive medium that it is taught me that I could not only swim under water, but fly!
Trying to become as fish-like as possible was an inspiring process of skill development.
Finally, I took the leap to scuba - and a counter-process that threatened to compromise these skills soon began. Instead of the exhilaration of underwater swimming, I started to notice flaws in training and equipment design that hampered my attempts to mimick fish-like movement.
Stiff rubber Jet Fins meant that, no matter how fish-like I felt inside, I just became more crab-like on the outside. OK, even crabs can swim, but all they can manage is a brief sideways scuttle before plummeting down to bounce clumsily over the rocks. Increasingly, diving equipment contrives to insulate us from the underwater environment, taking the same evolutional path as the crustacean carapace.
Cosmetic designs compounded the process. Sporty goggle-eyed masks, for example, can restrict peripheral vision and hinder accurate assessment of attitude and position.
Cruise missiles carry fewer protuberances than some sets of fashionable modern fins, which will pinion you to wreckage as effectively as a pair of anchors strapped to your ankles.
Snorkels with more valve array than a plumber's window-display drag like hooks at the mouth of any diver moving at speed. And, functional though the basic BC may be, even this has suffered at the whim of cosmetic design. Take the D-ring, which has little purpose but to embellish, and mischievously snags on everything from boat gunwale to seabed.
The idea of swimming well under water was never a priority for fashionable dive-gear designers.
Is there a bright side to all this? I believe that there is, but I suspect that it threatens the pride of many who consider themselves skilled divers.
Have you the courage to challenge yourself, not over how well you dive, but over how well you swim under water?
Drivers have to master controlling their vehicle before they can practise that control on the road.
A car is a cumbersome beast, and it requires both feet and hands to complete even simple manoeuvres such as parking or reversing.
Most driving divers master this skill easily, but how well can you reverse or park your own body under water, just by using your fins? Most divers seem to be challenged by such exercises.
Mastering control of the vehicle that is your body before deploying it under water is the missing chapter in diving manuals.

SWIM-BLADDER
Getting under water is the easy bit, like turning on the ignition. Modern diving equipment is dedicated to making submersion rather than manoeuvring easy, but for now it's the only hand we've been dealt. How best to play it? The answer is buoyancy.
Crab-like though we divers may appear, we have something the crab does not - an adopted swim bladder! Using the adjustable gas-bag we call a BC, we can float at any required depth.
Divers who claim to be able to adjust their buoyancy successfully using the air volume of their drysuit alone tend to conduct themselves under water with all the grace of a crash-test dummy.
A drysuit is a protective membrane with no buoyancy centre of gravity, and if you do manage to achieve neutral buoyancy this way, you're just a floating crab, not a fish. For all the stubborn bravado of such drysuit divers, the BC still provides more opportunity to obtain an extra dimension of control.
Constant adjustment of suit-air volume and BC buoyancy can quickly become instinctive through fine-tuning and practice, but this is only a start.

ATTITUDE
Fish can achieve neutral buoyancy, but have also mastered "attitude". Standing creatures such as humans think upright, and most BC weight systems give us mastery only of this posture. Fish, on the other hand, rarely "stand up".
To move more as fish do, adopt an attitude to "attitude". Most reef drop-offs fall at an angle between vertical and about 45°, so if you wish the part of your body with the viewing equipment to be closer to the show than the parts that kick it to pieces, your head needs to be closer to the wall than your feet.
For lateral progress in a supportive medium, a horizontal attitude beats the hell out of vertical.
If you are swimming over a flat bottom for much of your dive, attitude is even more critical.
If your feet hit bottom before your eyes, apart from the obvious environmental insult, nothing will be left after your Riverdance frenzy for your eyes to see. If, in this position, your only buoyancy control is your drysuit, you might as well prepare yourself for a handstand-dive.
Time and effort spent experimenting with buoyancy/weight is the only way to begin the process of underwater attitude control.
Let's face it, conventional diver-buoyancy training is limited to stopping you plummeting into the abyss. Don't underestimate the immense difference that accurate buoyancy control will make to the quality of your diving.

FINS
After buoyancy and attitude, the third component in evolving from crab towards fish is fin control.
Fish don't have hands but fins, and those that have residual hand-like fins, such as gurnards and frogfish, use them for groping the bottom, not for swimming.
On land, opposable thumbs and grasping hands have made us dominant in our chosen environment. But unless you're happy to be a crab diver, grasping limbs, like claws, must take second billing as propulsive devices.
Hands under water have few uses. When tilting uncontrollably towards a delicate coral reef, a single finger is sufficient for fending yourself off.
Holding a camera also needs hands, and good underwater photographers have no choice but to become competent underwater swimmers. As they will agree, there is an attainable stage of fin-control that renders hands almost unnecessary.
Using fins for anything but forward motion is a culture shock for many divers. To understand this limitation, we need to look at how our legs evolved.
The bottom half of our legs once took
a step backwards in evolutionary terms. Our mammalian ancestors mostly walked on tiptoe, as do most modern mammals. Their leg muscles in this configuration gave them a powerful spring action against gravity.
But when they took to the trees, the climbing environment encouraged upper-body strength and grasping feet, and the muscles of the lower leg took on a minor role.
When our ancestors returned to the ground, our grasping feet became little more than protective pads for the ends of our legs, having lost much of that spring action.
Look at Oscar Pistorius, the disabled athlete known as Blade Runner, who was not allowed to race able-bodied runners in the Olympics because his prosthetic spring feet were more efficient than those he had lost.
Our images of legend underline this fact. The form of the Devil Incarnate we adopt still sports the legs and lower muscles of a goat, to threaten us fleeing sinners with his superior speed!
This is where the picture brightens. Put simple unpretentious fins on those awkward human feet and, with a little practise with those disadvantaged lower leg muscles, you may not be able to outrun the Devil, but you could sure out-swim him!
These muscles may have been mothballed, but we retain a strong ankle with a unique rotary skill. Though a conscious effort is needed to release their full potential, they offer the possibility of a versatile swimming style unique in the animal kingdom.
Back-finning or back-sculling from side to side, using the muscles in front as well as at the back of the shin, is an art that doesn't come easy, but it's worth the price of practice. A rapid flip forward or backward using these same muscles can provide the thrust of a whole leg pedal, with a fraction of the effort and far less reef disturbance.
Under water, your body can act not only as a rudder but as a variable-geometry rudder!
Steering using no more than body-attitude in co-ordination with lower-leg fin balletics is not only a useful skill but an exhilarating experience.
In the dense medium of water, a gentle flip of both fins in unison while your body is arched forward will propel you in a forward circular motion with little effort. Similarly, feet and body twisted sideways will continue in a sideways arc with the slightest flip of your fins.
Using natural momentum in co-ordination with these body-flips will not only carry you across a delicate reef with minimal disturbance, but will also ensure that you consume less air than you would with energetic finning. Dolphin-like body flipping seems awkward at first, but practise soon makes fluid movement instinctive and effortless.
I discovered this in my early sport-diving days, when my favourite dive partners were those who consumed as little air as I seemed to do.
They also all seemed to move under water as I had learned to do - with minimal effort.
Next time you dive with buddies who seem to use less air than you do, observe them with this in mind. Remember also the relationship between nitrogen absorption and exertion.

TENTACLES
Into the crab-versus-fish equation comes the fact that we have only four limbs, while a crab has 10. Modern divers supplement these four limbs with extra appendages, sprouting in unfettered abandon from somewhere behind their head.
Contents gauges, direct feeds and consoles compete for dominance in the campaign to ensnare or bludgeon, but the drag co-efficient of this reckless array is an avoidable handicap.
Observe the octopus, which has the common sense to draw all its limbs together before engaging "drive". With a little effort, all our peripheral diving appendages can be kept within easy reach while tucked into the accommodating carapace of equipment.
How? Observe the octopus again. It has suckers, we have Velcro. Job done.

WARM-UPS
I'm not saying that freedivers are some kind of elite compared to whom scuba-divers are clodhopping idiots.
Let's face it, in British waters crab-diving can be appropriate. What use is it to be able to hover balletically 3m over a rock when, at that distance, you can't even see it.
Again, with the tidal range and currents our hardy marine life has to endure, it is well 'ard enough to withstand a bit of crash-landing and fin-abuse. The first occasion when a British diver is confronted by a dysfunction in his underwater finning technique comes when encountering a coral reef.
Warm seas and tropical reefs can offer an easier dive and a more intense visual spectacle than home waters, but delicate reef eco-systems are also more vulnerable to clumsy diving than a barnacle-encrusted rock off the Eddystone. The danger of becoming a bull in a fragile flower-shop is clear.
With unfamiliar rented weightbelt and BC, fins, once allies, conspire to become weapons of mass reef destruction. So why not "waste" that first dive in shallow water getting buoyancy and attitude as correct as possible?
Attaining any attitude better than vertical is a start in evolving from crab to reef-friendly explorer.
Finning styles and techniques are as individual as body type and size, and must come through with practice. But look at the fish beside you. The more parallel your body is to their axis, the closer you will be to swimming in harmony with the reef below.
Leaving the clamour of the world behind is one perk of sticking your head under water, but it's not the only one. Leaving the anchoring force of gravity behind completes the greatest equation for mental escape short of space flight.
Do you ever dive just for the sheer pleasure of swimming under water?