Monthly Archives: September 2016

  • Twenty Ways to Improve Your Diving

    Most Ocean Leisure customers are experienced divers who don’t need help improving their technique, but at the risk of teaching our grandmothers to suck eggs, here are a few suggestions and, who knows? You might spot a useful nugget among them!

    Get Your Trim Right. Often, divers carry the right amount of weight but in the wrong place. Consider where the fulcrum or pivoting point of your body will be. Integrated weight pockets on a BC might be too high up on a long-legged diver. A weight harness allows weights to be slung lower. On the other hand, a diver wearing a lightweight suit and using an aluminum tank might need to add some weight higher up and, if the BC in use has no trim-weight pockets, you can always add a couple of kilos to the camband that goes round the tank. You need to be comfortably horizontal in the water without any tendency to invert.

    Deploy a Marker Buoy Easily in Mid-water. Why do so many divers make a mess of this? Is it because they haven’t been shown how to do it? If you carry a big camera, learn how to do it easily with one free hand. Buoyancy changers appear to be the main enemy of a slick deployment. Using exhaled air to inflate the buoy avoids this because the buoyant air is simply moved from one location to another. Stream the buoy so that it floats above you. A tiny bit of exhaled air in it will help keep it up. Pull off as many metres of line that is practical, so that your reel hangs below you. Take the open end of the buoy and hold it with fingers and thumb above the upper side of the exhaust-T of your regulator while holding your head a little to one side. Have the line passing through but not gripped by your hand. Exhale into the buoy. It will start to ascend. Inhale again immediately releasing your grip on the buoy and grab the reel as it gets pulled up to your hand. Release the line from the ratchet of the reel. Watch the buoy go. Tighten off the ratchet, taking up the tension on the line, as soon as the line becomes slack because the buoy will have reached the surface.

    Carry a Flag. It was recently reported that Australian diver Jacob Childs spent a worrying afternoon alone, drifting at sea, before he was picked up. Childs had an inflated surface marker buoy, which is good for being spotted over a short distance but less good when in more dire circumstances. High-tech electronic solutions need to be kept fully charged and you don’t know if they are going to work until you need them. A low-tech solution is a big flag at the end of a long pole. Three lengths of plastic tubing that fit one to another and a length of elastic bungee running through the middle snap instantly together to form a tall pole with a large yellow flag at the top. When not in use it’s carried strapped under a couple of elastic straps round your tank. If you’ve dived in many remote places, most of which enjoy powerful currents and you’ve used it in earnest you’ll appreciate its efficacy. It’s low-tech, it’s cheap to buy, it can be deployed single-handed, and once used you wouldn’t go diving without it.

    Get Your Weight Right. The human body is more or less neutrally buoyant. Take a big breath and you float. Empty your lungs and your heavy head will go under. If we didn’t wear buoyant kit such as our suits, we wouldn’t need to wear weights. If you want to get your weight right, exhale hard at the surface and the weight of your head in the air should push you down. Add an extra amount of lead to compensate for the weight of the gas you might exhale out into the water during the dive and you’re perfectly weighted. So why do so many divers wear too much weight? Is it because they are used to plummeting to the seabed and trampling around before putting air into their BCD to make it back to the surface? Neutral buoyancy is the very essence of pleasurable diving.

    Long-Hose Your Octopus. The alternate air source you carry is not for you. It’s for use by another diver, in the event of his or her own gas supply being unavailable. Rigging your alternate air-source (octopus rig) on the left side of your body will ensure it’s the right way up and easy to use by another. It takes the drama out of air-sharing. Better still, employ a long hose of about a yard and a half or more so that they can use it without any drama for either of you. You can rig this long hose in a number of ways. It will be easy to stash under an elastic strap or two round your tank, as long as you can access it easily. Some advocate passing it under the right arm, tucked under a waistband, passing it up across the chest and round the back of the neck so that it becomes the primary regulator. They then pass this over if need be and go for an alternate second stage rigged where they know where to find it easily. Whichever way you rig it, make sure it’s visible and works properly at the beginning of every dive so that you’ll know it will work should it be needed in a hurry.

    Use a Regulator Necklace. Putting your regulator on a necklace arrangement is a good idea if diving in low visibility. If the hose gets snagged on something as you pass or a buddy accidentally hooks it out of your mouth, it won’t be going very far and you can soon replace it. A necklace is a good idea for your own alternate air-source if you are using a primary regulator on the end of a long hose as your primary regulator and likely to need to donate it. You can buy a purpose-designed necklace from your local dive store or make one yourself from surgical rubber tubing.

    Take Enough Gas. It’s obvious that for the same amount of work, a bigger diver will use more gas than someone smaller. It is also obvious that a bigger diver will be able to handle bigger tanks. If you are working to get good pictures, you’ll use a lot more gas than if you are just hanging about feeling slightly bored. Don’t battle to keep your gas consumption within the same range as someone else. Start off with sufficient gas to do the dive. This might mean requesting a bigger cylinder or even twinning up a pair of what’s available, using, for example,  twinning blocks and bands.

    Use a Current Hook or Reef Hook.  It’s a fact of life that big fishes are attracted to current points. That is to say, the places where the flow of water has to speed up to get up or around an obstruction such as a reef or wreck. It can be fierce. Some of the most notable places for observing this phenomenon are also known for the absence of any living coral on the reef top due to the fact that so many divers have clung on there. A current hook, so deployed that it attaches only to substrate or a handy rock, enables the diver to anchor in place while making himself slightly positively buoyant in such a way that he flies above the coral reef rather than ruining it by lying on it or colliding with it. What is a current hook? It’s an open-ended hook that can hold at its point, attached to some sturdy line or narrow gauge webbing that is clipped to a convenient D-ring on the diver’s BCD. Some local dive guides don’t allow the use of these hooks because they don’t trust their divers to use them responsibly.

    Wear a Suit That Fits Properly. If your drysuit fits your perfectly, there will be less of a drag when you are swimming. If your wetsuit or semi-dry is too big, cold water will flush around it under the arms and around the groin so that you’ll soon feel cold. If your drysuit is too small you either won’t be able to sit down in it or you’ll be limited to the choice of the undergarment you can wear with it. If your wetsuit or semi-dry is too small, it might interfere with your ability to breathe. If you can’t find the right size off-the-peg, get one made-to-measure. In the case of a drysuit, it might mean visiting the manufacturer a couple of times in order to get it right.

    Be Well Hydrated. Being well hydrated is not just a matter of drinking lots of water. In tropical countries the fresh water supplied in plastic bottles is often produced from seawater by reverse osmosis. This makes it pure but pure isn’t good enough. We need minerals in our water supply to get benefit from it, so make a point of adding a rehydrant powder or effervescent tablet to the designated amount of water so that it forms an electrolytic drink, at least once per day when away somewhere hot. Beer is a good rehydrant because it is mostly water and contains plenty of minerals but the alcohol contained within it suppresses the production of anti-diuretic hormones and you’ll just simply pass it through -- not to mention the brain damage that it gives you too. So the first beer of the day signals that you’ve enjoyed your last dive.

    Get Spring Straps. The single most important thing that can improve a pair of fins is the substitution of a pair of stainless-steel spring straps or elastic bungee straps for the rubber straps they were supplied with. It’s not just the fact that you avoid that embarrassing moment when a rubber strap breaks as you pull your fins on and you don’t have a spare with you. Spring straps enable you to pull the fins on and off in a moment and they contrive to hold your foot firmly in the foot-pocket of the fin. There’s no wobble and all your effort goes towards propelling yourself forwards. Stainless-steel spring straps are available for every fin that has an open heel.

    Entering the Water With a Camera. You’ve prepared your underwater camera housing by gently greasing the O-rings and making sure their grooves are free from detritus, but you still feel insecure about jumping in with it. Boat crews can be helpful, but they are not camera experts and they may mishandle it. You may be required to do a negative entry because of the current. Under those circumstances, coming back after jumping in for the camera to be passed down by a crewmember might well result in your missing the dive site entirely. Whether you’ve spent a few hundred dollars or more than $7000 on a camera outfit you’ll be just as circumspect when it comes to getting into the water with it. The best trick is to hold the camera in your hand, dip it into the water and, without letting go of it, follow it into the ocean. This works whether you’re on the swim platform of a big boat or doing a backward roll from an inflatable. It may not look elegant but it works.

    Hang About and Look. There’s a new kind of diver around, rather in the same way as there is a popular style of skier. In the Alps they call it ‘en-piste’. Many divers get in the water and spend all their time swimming to catch up with the diver in front. They don’t see what’s down there. They simply complete the dive. It’s rather like a skier coming down a blue run and never taking time to examine that breathtaking view. Take you time. Have a good look at what’s there to see. Get yourself a compact digital camera. They are easy to use, offer a high success rate with macro subjects, will give you an interest in the smaller animals, and you’ll come back with a lasting memento of every dive. If the dive-guide swims onwards, they’ll soon be back to find you, especially if they want to keep their job. Often. It’s the smallest things that make a dive interesting and it’s shame to be down there, swimming on endlessly in the blue without seeing it.

    Stalk the Wildlife, Don’t Chase It! Everyone seems to have an underwater camera now, but they behave very differently with it underwater than they would if they were on safari on land. Why? Do they think they are invisible? If you see a dramatic pelagic animal, don’t chase it. You won’t get a close-up picture that way and you’ll simply drive it away from everyone else. It has seen you coming and even Michael Phelps wouldn’t be able to overhaul it. Instead, avoid looking directly at it. Marine life is tuned to be threatened by the eyes of predators. Swim to where you think it might be going. Take into account what other divers who might have seen it might be doing. They can be employed as unsuspecting beaters. ‘Head it off at the pass’. The only way you’ll get close to it is if it swims up to you. Turn yourself into an ambush predator. As old-time jungle hunters used to say, “Slowly, slowly catchee monkey.”

    Learn to Line-lay. If you penetrate a wreck or other overhead environment, you should lay line. The late Rob Palmer, doyen or early technical divers, used to say that line laying was an art. If you enter a wreck or cavern and are intent on finding your way out, it’s a good idea to copy Theseus with his ball of string. In the Greek legend, he found his way out of the Labyrinth after slaying the Minotaur. Lay it on the way in and follow it on the way out. The problem comes when the water moves -- and wrecks and caverns offer more hazards than any Greek mythological hero encountered. You can inadvertently pull a line into a place that it will snag and will not allow you to follow it back, or some other diver can inadvertently do that for you simply by the downwash of his fins. Belay the line as you go, tying it off at various convenient points so that this can’t happen.

    Get Your Kit Off Easily. When you get picked up by someone in a boat, there’s a good chance you’ll be close to what might well be a boat hazard, such as a reef with breaking waves. The wind might well be pushing the boat that way. It’s imperative that you can pass up your weights and any loose items you might be carrying, and get out of your gear in a timely manner. Inflate your BCD so that nothing will sink beyond reach. With your regulator still in your mouth and your mask and fins still in place, unclip the sternum strap and waist strap and one buckle at the shoulder. You can now swing the whole thing off your right shoulder while still holding on to the grab line of the boat with one hand. Push up from underneath to help the boatman avoid a hernia. If you have a one-piece harness with no shoulder buckle, the best thing to do it to pull it over your head. Actually, what happens is that you duck underneath it as its weight pushes you down. Keep your mask in place until you are safely in the boat. So often the mask is one of the first things that gets passed up. It makes the diver vulnerable because they can’t see what’s going on underwater and the mask vulnerable to getting broken in the bottom of the boat too.

    Learn How to Access a RIB or any Inflatable. Why is it that some younger people cannot climb easily in and over the inflatable tubes (sponsons) of a RIB from the water yet most old-age pensioners can? It’s because nobody has shown them how to do it? It’s not about strength. It’s about technique and knowledge. First choose the tube on the side where everyone is sitting. The other tube will be higher out of the water. Once you’ve passed up all your gear save your mask and fins, take hold of the grab rope (they are properly called ‘beckets’) with your hands about equal to the line of your shoulders. Take a breath and push vertically downwards as hard and fast as you can. You’ll momentarily fight your buoyancy, which will send you rushing back upwards. Fin hard at the same time to get as much upward velocity as you can. Straighten your arms, locking out, and tilt your head and chest forwards over the boat tube so that you tilt into the boat. Bring a knee up onto the tube. You’re there. Get someone to help you off with that first fin if need be before bringing the other leg inboard.

    Wear a Hood. Some people think that wearing a hood is done to keep a diver’s head warm. Well that is obviously the case and although medical men might argue about how much heat is lost through the head, your brain has an exceedingly good supply of blood and there’s precious little fat on most people’s head to insulate that from the cold water. There are other reason’s to wear a hood too, and that includes when in tropical waters. Tropical waters are rich in zooplankton and much of it carries nematocysts or stinging cells. The less skin you leave exposed the less chance you’ll have of suffering an irritating sting. Gentlemen who sport a moustache and leave plenty of stubble in place on their faces find it protects from the man-eating zooplankton too. Ladies might not have that option. Another reason for wearing a hood? When you are at the surface there’s a lot of ultra-violet light on your head and it’s reflected from the water. A hood keeps you from getting sunburned.

    How to Wear Wetsuit Boots. Why do you wear socks with your shoes? You’d probably get blisters otherwise. Many experienced divers wear a pair of socks with their wetsuit boots for the same reason. Try a pair of seamless airline socks. You know the type. They often give them to you on long-haul flights. Sophisticated socks intended for runners are constructed from two layers. So try two pairs of airline socks. Result? Luxury! Wear two pairs of seamless socks with your wetsuit boots and you won’t look back. They have the side effect of making it easy to pass your feet through the legs of your wetsuit too.

    Use a Weight Harness. Instead of strapping a lot of lead around your waist where it might ride up or slip off your hips, or instead of using an integrated-weight system of a BCD that might lead to your weights being positioned too high up your body, which in turn puts your fulcrum too far from your feet (leading to inversion in a drysuit) use a weight harness. By adjusting the supporting shoulder straps, you can wear your weights down by your hips. This not only makes carrying the weight more comfortable, but it puts the ballast where it needs to be. A properly designed weight-harness allows you to drop the lead in an emergency yet keeps it totally secure at all other times.

     

  • Photographing Sharks

    It’s easy to impress your non-diving friends and neighbours with the photographs you might take of sharks. Shark encounters come in a number of types: Chance encounters such as you might get ocean-roving oceanic white-tip sharks, encounters where currents attract requiem sharks that enjoy surfing on the flow, encounters with bottom feeding sharks such as nurse sharks and leopard sharks that like to lie up and rest during the day, and where sharks are feeding.

    The normal rules of underwater photography apply, in that it’s best to use a wide-angle lens and get as close as possible. Reduce the amount of water between your camera and the subject.

    Oceanic white tip shark Ocea-roving oceannic white tip shark

     

    Ocean roving sharks tend to be close to the surface so it’s quite possible to get reasonable pictures without an underwater strobe or flash but these are ambush predators so designed as to offer a low contrast image to intended prey. A correct flash exposure can give contrast and add drama.

    They tend to swim around 6m deep, constantly investigating anything that might be the source of a meal. That is why they approach divers, often only to turn away at the last moment when they consider us to be animals too big for them to take on. Sharks appear to judge size by height rather than length so if you want a shark to come close, present as small a frontal area as possible by being horizontal in the water. Go vertical and you will almost certainly scare off such a shark.

    Those sharks that lie about during the day such as nurse sharks can be approached with caution so as not to disturb them and you will have time to get more than one exposure adjusting the lighting and exposure to suit. The same can be said of white-tip reef sharks, although these are much more skittish. They lie about on the seabed during the day because they are able to force oxygenated water through their gills without forward motion like most other requiem sharks, but be aware that because they are grey and again designed for ambush, they need careful lighting just the same.

    Scalloped hammerheads at a cleaning station Scalloped hammerheads at a cleaning station

    Then there are the cleaning stations. Find out from the local dive guide which fish are the resident shark cleaners and find where they are aggregating. Then you just need to be patient, keeping as still as possible, waiting for the sharks to approach for a visit to the manicurist. It’s the only way to get pictures of scalloped hammerheads because they are so skittish. You need to sort out your overall exposure so that the background is reproduced an acceptable blue, adjusting the power of the flash (or strobe) to suit the foreground shark.

    When it comes to feeding sharks, things become a lot more frenetic. You need a fast shutter-speed but you will be limited to the fastest speed with which your camera will allow you to synchronise your flash.

    Sharks feed in two distinctly different ways. When chasing live prey they become very agitated and it’s best to keep clear at this time, even exiting the water. Sharks have more senses than we do but it’s a fact that they have a nictitating eyelid that covers their eyes to protect them at the moment of biting so that they virtually do the last part of an attack with their eyes closed. Mistakes can happen. Anyone who has attended a night dive at Manuelita Island near Cocos will attest to the fact, it can be chaotic, and that’s when it’s only little white tip reef sharks start hunting small fished by the light of the divers torches. Bigger sharks can explode with energy when they sense a live prey.

    White tip reef sharks competing for live prey at night. White tip reef sharks competing for live prey at night.

    On the other hand, when sharks sense there is a meal of carrion to be had, they are much more leisurely in their approach. There are no vibrations of injured or dying fish to excite them or ring their dinner bell, just the odour of an easy meal wafting on the ocean currents. So they tend to swim round in an orderly manner.

    Staged shark feeds such as they often do in the Bahamas and some parts of the Caribbean will give any diver witnessing the event that sharks, although impressive beasts, have a pecking order and act in an orderly manner so that they do not risk injuring each other. They still move quite quickly so you will still need to choose the fastest shutter-speed you can, in order to get sharp pictures. If you do not, the flash will record a sharp image but there will also be a less sharp ghost image due to the daylight exposure being too long.

    Using twin flashguns can also be counter-productive because those guys in the grey suits need a bit of contrast to light them up with plenty of shape and contour. It’s one occasion when the single flashgun reigns supreme.

    Caribbean reef shark at a staged shark feed. Caribbean reef shark at a staged shark feed.

    With plenty of sharks attending a staged feed, you won’t be able to judge where any are at a given moment. You’ll need to take a lot of pictures because inevitably one animal will obstruct your view of another, many times when you release your camera’s shutter. If you shoot RAW files, you’ll be able to adjust these after the event and not have to keep adjusting your flashgun’s output to account for sharks being at different distances from the camera.

     

     

     

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