If you are considering liposuction, the time you will have to wait before engaging in recreational scuba diving varies on the type of procedure you are going to try. The average wait between the liposuction and your first dive will usually be between three weeks and three months, depending on the amount of fatty tissue removed and which type of liposuction you opt for.
Recovery time also depends on how many areas of your body you decide to focus upon. For example, if you have three areas of your body that you feel need improvement, you could either have three separate procedures or one much more prolonged one. If you opt for the latter, you only require one period of recovery, but that period will be longer, and the procedure itself will be longer and will carry more relative risks. The risks involved with general anesthesia also increase the longer you are subject to it. If you have all three areas dealt with on separate occasions, the risks will be lessened but you will have three separate recovery periods to undergo before you can return to scuba diving .
Conscientious, contact-free diving means diving in control at all times. You should constantly be aware of where you are in the water column. If your buoyancy is under control you won’t unconsciously float up or sink — or if you do, you’ll immediately recognize the situation and correct it.
Good buoyancy control alone is not enough, however, to guarantee that you’ll avoid accidental contacts while underwater. You also need to develop awareness of where your entire body is in relation to surrounding objects. This is especially important when night diving and maneuvering in confined spaces such as wrecks.
It’s easy to fall into the trap of thinking that where your head goes, so goes the rest of your body. We secure our hoses and accessory gear so they won’t hit anything, but often pay little attention to where our fins are as they flutter along behind us.
One of the ways to prevent fin contact is to move slowly and gently. Envision yourself as part of a delicate ballet, a troupe of dancers gracefully executing precision movements to the rhythm of the flowing waters. This metaphor works for me, anyway; you can create your own vision to help you blend harmoniously with whatever underwater environment you’re exploring.
When you are a guest in somebody else’s home (in this case whatever aquatic creatures live where you’re diving) you do your best to fit in and to avoid disturbing or damaging it. Moving slowly and carefully through the water column allows you time to develop continual awareness of every part of your body. For instance, you’re swimming along, approaching a bottom feature protruding from the substrate (e.g., piece of a wreck, sea fan, giant anemone). Consider in advance how you will clear it and by how much. “Shall I go over or around? Am I horizontal or are my legs lower than my torso? I have 6 inches vertical clearance, is that enough for my kick to clear’?”
If you conclude that you might not entirely miss the object, you have choices. One is to change course and kick around it, if possible. This option keeps you at the same depth and lets you view the feature from the side rather than the top. Alternatively, if the feature is large you can kick upward and pass well over it, adjusting your buoyancy as necessary.
Another option, if you’re near the top of the object, is to simply inhale deeper and glide over it. This is the most relaxed response, involving no noticeable body movement, but requiring an awareness of how your personal buoyancy is affected by your breathing pattern. Still another choice is to change your kicking style to one that will avoid contact. In Open Water class we’re taught to use the flutter kick as our standard means of propulsion. It works well for covering distance, but for moving slowly or in close quarters other styles are preferable.
One of my favorites when I want to swim near the bottom without disturbing it is the side kick. This is basically a flutter or scissors kick performed sideways — the stroke is parallel with the bottom instead of toward it. Twist your body at the waist so you are still facing forward, but your hips are rotated 90 degrees. Since the fin strokes push the water sideways rather than down, little turbulence reaches the bottom and the chances of contacting it are minimal. A Variation on this is the bent-knee flutter used by cave divers. This does not mean bicycling. The body stays in a straight line from head to knees (i.e., don’t bend at the waist). The kick is from the knees and the downward stroke stops with straight legs and the body aligned, rather than continuing downward.
The frog kick is another option. The knees are brought forward and out to the side with the ankles bent so the fins stick out, like a frog. Then the knees are quickly straightened and the toes are pointed, so the legs snap together (watch a frog for the best demonstration). Again, the force of this kicking method is toward the back rather than up and down, so it can be used near the bottom.
The amount of propulsion from the frog kick depends on how far apart the knees are extended and how fast the legs are brought together It is a good alternative for gliding slowly around a site as well as for maneuvering through a tight swim-through.
The ability of light to pass through water (and our ability to see clearly) is also influenced by its turbidity. Turbidity is influenced by many factors but they can be grouped into two large classes, things suspended in the water and things dissolved in the water. Suspended things include silt, plankton, etc. while dissolved things include salt and chemicals. When a diver is swimming along near the bottom, the water movement caused by their fins often stirs up the silt and for a while the water behind them has high turbidity this often results in death when open water divers enter caves. The water is crystal clear in front of them and they do not realize until they turn around that they have been kicking up the silt and they can no longer see the way out of the cave.
If the water is still, the silt will eventually settle back down to the bottom and the water will become clear once again. The time this process takes depends upon the size of the silt particles. Grains of sand will settle in a minute or two while the ultra fine grains of rock flour produced by a glacier will take several weeks to completely settle out. During a cave diving trip under the Columbia Ice fields in 1987 the water was ‘air clear’ when we arrived at the dive site. After we had made the area safe and several hundred (or thousand) kilograms (pounds) of mud and rocks had been dropped into the water, the visibility was less than 2.5 cm (I inch)! We went back to the surface and returned to the dive site two days later. The silt was so fine (glacial flour) that even though the water was absolutely still, the visibility had only improved to 30 cm (12 inches).
Salt water has large quantities of salt and other chemicals dissolved in it and for this reason, can never he as clear as fresh water. The best clarity to be found in the ocean would be around 60 meters (200 feet) while in some fresh water caves the water is so clear it cannot be seen, visibility is over 300 meters (1,000 feet). These ideal conditions are rarely encountered and we usually have much less visibility. For example, the Ottawa River contains water with many dissolved chemicals (from soil, trees, etc.) and visibility is seldom more than 6 meters (20 feet). The St. Lawrence River used to be similar but the infestation of billions of zebra mussels has changed this situation drastically. Zebra mussels are filter feeders and each mussel filters the silt and chemicals out of a large amount of water every day. The result is that places where 6 meters (20 feet) visibility used to be considered good now frequently have 30 meters (100 feet) visibility or snore. The problem is, now that the water is clear enough for divers to see well, the wrecks still can’t be seen because they are now covered in many layers of zebra mussels!
The next major change in our vision when we are diving is that the colors often seem drab. This is because water absorbs light. Colors are simply light of different wavelengths and water absorbs them at different rates so that after light has passed through about 5 meters (16 feet) of water, most of the reds are absorbed. After 10 msw (33 fsw), the oranges are also absorbed.
The yellows disappear next followed by the greens and blues so that by the time we are deeper than about 20 MSW (66 fsw), everything appears bloc / grey. Using artificial lights restores the colors but the light from an underwater light is not exactly the same as the light from the sun and the colors will not be quite the same as if the object was out of the water.
The amount light is focused when it passes through the cornea is due to the difference in density between air and the cornea. The cornea has a density almost the same as water and therefore the difference in density between water and the cornea is very small. When light passes from water to the cornea, very little focusing occurs and the light will not be in focus until it is behind the retina. Therefore, when we open our eyes underwater everything appears blurry!
The solution is to wear a dive mask. The dive mask creates airspace in front of the cornea, allowing the normal amount of focusing to occur when light passes from the air to the cornea, giving us the same vision as on the surface. Nov that we can see clearly, we notice that everything appears larger underwater than it does on land. What is going on?
The glass in the dive mask has almost the same optical properties as water and therefore very little focusing occurs as light passes front the water into the mask lens. However, the density of the mask lens is much greater than the density of the air in the mask. As light passes from the mask lens into the airspace in the mask, it diverges (the opposite of focusing)! This results in objects appearing larger than they would out of the water. The magnification is about 25%, so that a 40 cm long fish will appear to be 50 cm in length. Exactly the same mechanism occurs when we look down into very clear water from above the surface (light coming from the fish diverges as it passes from the water into the air) so that fish we see in the water appear 25% larger than they really are.
We have several mechanisms for helping us determine how far away an object is. One is the apparent size of the object. We know how large our dive buddy is on the surface at various distances (they appear smaller when they are farther assay). When we look at our buddy underwater, we notice how large they appear to be and use our experience on land to determine how far away they are. The problem is that underwater they appear 25% larger than they do in the air and thus we think that they are 25% closer than they actually are. If we reach out to touch them (or anything else) we may find that our arm is too short!
The bottom line is that underwater things generally appear to be 25% larger and 25% closer than they really are. Therefore, divers have a much better excuse for telling stories about how large the fish was than their above water friends!
Before each dive, work with your students to closely examine the objects of their fear, help them rationally weigh the risks, and then develop a sound procedure to control the perceived risk or danger. By teaching our students to perform such an analysis, the stresses associated with common fears and concerns can be relieved.
The Cycle of Stress and Panic
It’s important for our students to understand how too much stress can lead to panic. As part of the discussion, we can review how an accumulation of stressed causes an increase in heart rate, as well as rapid shallow breathing, the result being a buildup of CO2. Especially when breathing through a regulator, a diver can experience a real or perceived inability to breathe, or increase in breathing resistance, that heightens the stress and leads to panic. Oftentimes, a panicked diver will remove his regulator or mask, causing a more dire situation. When a diver understands this cycle, he is better prepared to deal with stress, and may be more likely to take steps necessary to alleviate common stressed.
The Signs of Stress
The closer we get to the water, the more important it is to carefully monitor stress levels, so part of our efforts in teaching about stress must focus on identifying the signs of stress, and taking actions to alleviate it.
A variety of subtle and not-so-subtle signs can let us know when a diver is experiencing elevated stress levels, and we should review these with our students both in class and as we prepare for an in-water exercise. Before a dive, we might see changes in personality. While one diver might become “distant” or preoccupied, another might become giddy or start laying on the one-liners. A diver who becomes forgetful or who has problems assembling his gear, or who becomes angry or frustrated may also be experiencing elevated stress levels.
Physiological stress can also be building in the pre-dive period. A fully suited diver sitting in the sun may be overheating. A diver who becomes overly quiet and looks pale could be experiencing the onset of seasickness. Remind your students that physiological stress can add to or heighten the psychological stress of a dive.
Once in the water, a number of signs may become apparent in divers who are becoming stressed. Our students should know to look for wide eyes, a high breathing rate, and flailing of the arms that signal a diver’s stress level is high or on the rise. A diver who “freezes” to the boarding ladder or down-line might also be experiencing high stress levels. When a diver is fumbling with equipment underwater, or appears to be having some form of equipment problem, chances are his stress level is rising.
The time to be thinking about stress is long before it becomes a problem. One technique that can help students be on the lookout for stress is to instruct them to take notes (mental or written) regarding the signs of stress they see in themselves and others before, during and following a pool session or open-water training event.
When students are tuned in to looking for these signs, they are more likely to identify them. Follow-up after the pool or open-water training will help reinforce what they have learned, and help them develop better strategies and techniques for avoiding stress.
While we can always tell our students to just relax and enjoy the dive, several steps and procedures are more likely to help a diver relax before a dive. One key to maintaining confidence and alleviating stress is to review the plan for the dive, the normal and emergency procedure to be used, and underwater hand signs for the dive. Reviewing these items will help the diver develop a confident frame of mind and become mentally prepared for the challenges ahead.
The eye is really just a complex, living camera. The main parts of the eye are the cornea, the iris, the lens, and the retina. The cornea is clear and has no blood supply It protects the eye but its main function is to focus the light that enters the eye on the retina. A diopter is a measure of the power of a lens and the power of the cornea is equivalent to a +43 diopter lens. It is composed of five layers but for simplicity can be thought of as having a thin layer on the surface (epithelium) and a body composed of flat stromal cells. The epithelium has many nerve endings and therefore, when we get a hair or some other foreign body in the eye and scratch the cornea, it hurts a great deal!
After passing through the cornea, light crosses the anterior chamber and then goes through the opening in the iris called the pupil. The iris is a muscle and forms the colored part of the eye so that when we say someone has blue eyes or brown eyes, we are really saying that their iris is blue or brown. The iris functions the same as the aperture in a camera; it leaves a large opening when the light is dim and a small opening when the light is bright. This controls the amount of light that enters the posterior part of the eye.
When we are excited or frightened the pupil dilates, allowing more light into the eye and allowing us to see more clearly. Men consider women more beautiful if they have larger pupils (they assume the woman is excited to see them!). Women in ancient Egypt used to rub juice from the belladonna plant (contains the drug atropine) in their eyes to dilate the pupils to make themselves appear more beautiful!
Light has to be ‘bent’ just the right amount so that it is focused on the retina for us to see clearly. Light from objects that are far away has to be ‘bent’ less than light from near objects. The purpose of the lens is to change the refractive power of the eye to accommodate for objects at different distances. As the ciliary muscles contract, they release the tension on the suspension ligament of the lens and the natural elasticity of the lens capsule causes it to assume a more rounded
shape. In a normal eye light from distant objects is focused on the retina with the biliary muscles relaxed. To focus the light from near objects, the colliery muscles contract and the lens becomes rounder, increasing the focusing power of the eye.
When light hits the retina, a series of chemical changes occur which generate an electrical signal that is transmitted to the brain and through a very complex process translated into the images we see. Now that we have a basic understanding of hose the eye works, what happens when we try and see underwater?
J4, or Scratchers Sub is by far the most popular mostly due to its depth at 27 meters, but also because it is such a great dive. It’s broken at the torpedo room, with the bow twisted away to port. Like all the others, the bow plating has collapsed, leaving the tubes exposed. It can have an awesome amount of fish on the inside, and I have film of the entire interior filled with bull’s-eyes and pike. Blue devils may be found around the bow section, and there used to be a resident conger eel in the control room.
Because of available bottom time, this is the best sub to study. Most divers have a quick look at the bow section, and then enter the wreck through the break. Light streams in through the deck holes aft.
Making the control room under the conning the darkest part. From there you can make out the two engine bases side by side in the forward engine room, and then the single engine base in the aft engine room. The prop shaft flange is clearly visible at the base of a large bulkhead with a number of hatch ways to the next compartment. Further penetration aft is constricted through crew quarters and steering room to the aft most hatch and should only be attempted by experienced wreck divers with a narrow profile setup.
The hull of the J4 is mostly weed and algae covered, with a healthy growth on top of the conning. There’s always perch and sweep around the conning and plenty of leather jackets around the wreck, but please don’t feed them as they are starting to nip! The wreck sits upright in heavy reef in a roughly north south orientation, which can make it pump with the groundswell certain clays, so it’s advised to wait a while at the entrances to feel for surge before entering.
As well as the famous subs, there are three coastal traders scuttled near Point Lonsdale. The most popular is the SS Coogee, sitting with a 40 degree list to starboard in 33 meters. Built in 1887 at 762 tons, she was scuttled in 1928 near the subs. She’s now mostly collapsed, leaving the bow section, boilers and stern standing above the sea floor. The stern is one of our prettiest reefs, artificial or not! The upper deck has collapsed, exposing the steering quadrant and framework; all smothered in yellow zoanthids and decorated smith sponges. It’s swarming with fish; mostly perch, but also lots of sweep, leatherjackets, svrasse, and queen snapper. Pike cruise just off the wreck and the cave between the rudder and hull is packed with bull’s-eyes and sandpaper fish.
Old wives mingle with bull’s-eyes around the boilers, and usually a blue devil is found in the fireboxes. It’s a short swim over flattened wreckage to the boss; also well encrusted with sponges. Perch play in the deck railings and bull’s-eyes fill the interior. Don’t forget to look under the plating or around the inside of the deck hatches for crayfish feelers, or cuttlefish. The Coogee is a great wreck, or reef dive!
Although very similar in layout to the Coogee, the wreck of the Rotoinahaiza is significantly bigger at 1777 tons, and significantly deeper at 40 meters. Built in 1879, she was also scuttled in 1928, but a bit further west than the subs. Again she’s mostly collapsed, leaving only the stern, boilers, and bow proud of the seabed, though there are more mid-ships to see than the Coogee. Being deeper, she’s not as rich in growth, but not far behind with fish life.
Also scuttled in 1928, the 728 ton excursion steamer SS Courier has become our prettiest shipwreck. Broken into three main sections on a white sandy bottom at 43 metres due south of Point Lonsdale, the Courier has become an oasis for marine life in a sandy desert. Being in line with the in and out flow of Port Phillip Bay, she’s been bathed in nutrients and is richly covered in sponges, ascidians, hydroids, and bryozoans. At times she can be obliterated by schooling fish, and there’s always healthy schools of perch swarming around the stern. Bearded cod dominate around the boilers, and are much paler than those seen elsewhere. This is a place to see the unusual animals, and usually with a spectacular backdrop.
Due to the depth it isn’t usual to see all this wreck in one dive. The bow section lies on its starboard side and is totally encrusted. It allows limited penetration and a flossier will find ceramic tiles in place under the silt. Most decking timber has gone, but only in the last 10 years. Close by are the heavily encrusted boilers with wreckage to either side. Mosaic leatherjackets, cutlets, and bearded cod live here, but big schools of fish like warehouse can also be encountered. The trail of wreckage aft of the boilers leads to the stern, most of which is metal framework covered in white, pink and apricot jewel anemone. The rest is smothered in sponges of all sorts. Some ceramic tiles can also be found Isere.
Several times dolphins have visited us on the deco line; a pod of eight common dolphins once played with us for 40 minutes, allowing Mary to get out of the water to change film, and then rejoin the fun!
The newest addition to our scuttled fleet wills him the 139 meter 4100 tone guided missile frigate, LIMAS Canberra. Scheduled to be scuttled in 2008 in 35 meters, near to the Rotomahana, divers will be able to start their dives at the mast array, making their way down to the gun deck to explore the upper superstructure, or make deep dives past the main deck to the sand. Penetrations will be possible for suitably experienced and equipped divers through the many diver access holes cut into the vessel.
The most popular dive will be to descend down the funnel to the engine room, inspect the huge gas turbine engine and exposed gearbox, then head off into the adjoining auxiliary equipment rooms. From there they can make their way through the mess, officers quarters, and up to the bridge, before ascending the mast to finish their safety stops on the mooring under their dive boat.
Of course there trill be many other parts of the ship to explore on subsequent dives, or just check out the schools of pike, perch, sweep, warehouse, bull’s-eyes, leather jackets, mowing, kingfish, and occasionally snapper which will visit and live on the wreck.