“Full Ahead Backwards!” I just love being in charge of a dive boat and giving the orders. Many of them I learned while listening to The Navy Lark on BBC radio when I was young. “Right hand down a bit!”, to a helmsman when turning to starboard, was one of my favourites. Since I was Captain of my own boat for many years, I could do whatever I wanted. Well … not quite. The other thing I say is “I am the Captain of this ship, and I will do anything my wife suggests!” My wise father taught me this, and he was not even a sailor.
Recently I thought about the challenges of successfully running a dive boat. You have to be able to find the dive sites, but this easy with today’s GPS navigation. When I started all I had was a hand bearing compass and sketch book in which I would draw “transits” I could line up to get close to the site. It could be very tricky, but I took some pride in my skill and rarely failed except when the weather blotted out my marks. If finding individual sites is easy nowadays, deciding the order in which they should be dived is more complex. Let us suppose we have a ten day dive cruise to manage. Where do we go first? My first move was to consult the tide tables. I could tell the smaller neap tides from the larger springs, and plan to dive the sites where too much current can be a problem during the neap period. I also liked to make the first days diving fairly easy to allow for our diving guests to get back into the splash of things. Then, later each day, I have to be able to get to an anchorage. Sometimes the weather would make the decision easy for me. Strong winds meant heading for sheltered sites whatever the tide was doing. Other factors that would come to play were visibility, marine life, health of the dive sites, depth of the dive and interests of the divers. But eventually I had to make A Decision. After I made decisions I often found my judgement questioned. Sailing out of Port Moresby to the barrier reef was always a hassle in the trade winds. Early in the morning the harbour could be mirror calm, but looking out to sea I could spot the whitecaps. A land breeze made the harbour calm, but as soon as you pointed the bow at the outer reef the swells told me we were in for a rough ride. I knew then that we would only be able to dive the inshore islands but found that to persuade the guests I often had to head out and slam into a few waves. As soon as they started to don their life jackets and ask about cyclone season I knew it was time for me to turn back to the islands. If they really annoyed me I would make a maniacal laugh and remark about how exhilarating it all is and keep going until they begged to turn back. Now I do not have the desire to play those games. I make my decision and, unless new information forces me to change my mind, or Dinah corrects me, I head to the declared dive site. If any one annoys me I just tell them that the last diver who did that mysteriously disappeared overboard. Sometimes I get it wrong and find the site is going to be difficult to dive. Now I have to make the really important decision to dive or abort and go somewhere else. Mostly the pressure is on from the guests to make the dive, and I have to go through my own checklist of things that they may have little understanding of. “How safe will the boat be?” is the most important. I may decide the dive will be safe if I stay on board, particularly if the mooring is not as secure as I would wish. In this case I remind the guests that although we have plenty of divers, we only have one boat and it is a long swim home. Then I need to consider how safe the divers will be considering; their apparent experience and whether they can cope with conditions; how I can get them in and out of the water or dinghy; where they are likely to end up. I have to think about whether the dinghy will be swamped, or even flipped, if the wind is blowing. This is where I can call on 30 years of awful memories. If in doubt, I’ll bail out and take the boat elsewhere even if it means an hour or so delay in diving. What I am doing is assessing risks and making a prediction as to whether the dive will be safe. That means I predict it will be unlikely, but not impossible, that an accident will occur. I remember that risk can be addictive. Then I think of my “Captain Cook Cup Of Tea Theory Of Risk”. Basically if Captain Cook had had a cup of tea instead of going ashore at Hawaii, he would still be alive today. He would be 277 years old but I hope you see what I mean. Sometimes it is better to sit back rather than take that extra risk. Have a cup of tea. That is a wonderful decision. “Musical Tanks” was a game I played in the pool as a training aid for scuba divers. I learned it at my NAUI instructor course in 1970 when most scuba divers were also experienced breath-hold divers (skindivers). All the divers would remove their tanks but be breathing from them on the bottom. I would then swim down and tap one on the shoulder which meant he (or she) had to give me his regulator and, blowing bubbles, move on to another diver and tap him on the shoulder. So divers were moving from one tank to another. Then I would start removing tanks so that eventually the divers were competing for just a few tanks. If any diver came to the surface, they were out of the game. The trick to winning was breath control. If I saw another diver was competing with me for a tank I would wait, blowing tiny bubbles, until he took the regulator then immediately tap his shoulder and he would have to give the regulator up, still short of air and usually off to the surface, but allowing me several breaths before another diver tapped me. This was good fun, especially as I got older (and more treacherous). I taught my pool classes mostly without a tank on. I could demonstrate mask clearing (several times) on one breath after already breathing out a bit to get on the bottom. I blew the water out, but did it gently so no air escaped the edge of the mask. You should try this. See how many times you can clear your mask with one breath of air and no spillage. Half a dozen times with a standard mask should be easy. You will need a weight belt, but should not have any more weight on than if you were scuba diving. I was reminded of all this by underwater model Leigh Paine, a good scuba diver and professional violinist, when we were shooting promotional shots underwater with a useless violin. We did this without scuba in a pool. She was wearing a concert gown with a weight belt underneath, but no mask, snorkel or fins. I told her “Just breathe out, sink to the bottom, pretend you are making beautiful music, and I’ll take a couple of shots. I’ll have to wait a few seconds until the surface is calm enough to get the palm trees in the background. Remember to pull the dress down, keep your eyes open and your elbows in, and don’t forget to smile.” At first she descended perfectly – but then dashed straight back to the surface again. She was breathless far too soon. Evidently there was an instinctive barrier to breathing out, then holding her remaining breath. She was experienced underwater with nearly 200 dives logged, but I realised that she had never played breath-holding games, had never done skindiving and was not trained to hold her breath whether her lungs were full or empty. Most people never try holding their breath at all, and why should they? But divers will benefit by getting used to the sensation of increased CO2. If you can tolerate the discomfort of a minute or two without breathing, whether you are gently exhaling as you would if you had to make an emergency ascent without air, or whether skin diving to 20 metres or just swimming a length of a pool underwater, this gives you a certain confidence in a situation where you may be unable to ventilate your lungs immediately, and thus avoid panic. If you panic underwater, death is a likely outcome. So Leigh started to practice some underwater breath holding, soon became relaxed and proficient, and the resulting photo is what we wanted, and perhaps even breathtaking. Here is a test for you to try; my bet is that you will have to practice. Wear a normal weight belt and snorkelling gear. Dive down to the bottom of the pool and remove your fins, mask and snorkel, and leave them neatly on the bottom. Ascend to the surface, take a couple of breaths then sink down by breathing out a bit (you still have your weight belt on), put on your fins, then your mask. Clear your mask, blow a bubble ring, put your snorkel in and ascend through the ring, clearing your snorkel underwater with your last puff of air. Arrive at the surface and snorkel without raising your head, without choking and without spitting your snorkel out and crying “help!” In other words, be cool. If you do not know how to blow a bubble ring, this is the method I use. Lay on your back with your snorkel (or regulator) out and your mouth pointing upwards. The water needs to be free of current and surge – practice in the pool. Make an “O” with your lips and stick your tongue in. Then cough a little air though your lips while moving your tongue back and forward quickly. Just blowing does not work; you have to cough the air using your diaphragm. If the air ring breaks up you have not mastered the technique yet. Keep practicing until you can blow a series of perfect rings – the effect is almost magical – and you will even find that if you blow two in quick succession that the second will move through the first as they rise to the surface. A word of caution is required. If you practice breath holding or skin diving it is a good idea to have someone around watching you. Deliberately hyperventilating before a dive will extend your breath-holding times and allow you to skin dive deeper, but it comes with a risk. If overdone it can drive your CO2 levels so low that you pass out on ascent through rapidly falling partial pressure of oxygen (O2) This is “Shallow Water Blackout”. Remember, build up of CO2 is the trigger for breathing, not a lack of O2. Without hyperventilation, the build up of CO2 in your body will usually force you to breathe before O2 gets too low. Here is something you can try at home without getting wet. Practice breath holding and time yourself. Most people can do one minute, far fewer two. Get a friend to write a simple mathematical problem on a folded piece of paper. Something like 27 divided by 5. Take your confident best breath holding time and subtract 20 seconds – normally enough time for you to solve the problem (no calculators!). Have the paper in front of you, hold your breath for the new time, open the paper and solve the problem BEFORE breathing again. You will find it hard – you will want to panic. Now imagine yourself underwater without air and a problem to solve. Are’nt you glad you have some breath control and have practiced all your skills so you do not have to think about them? Stick around, next time I’ll teach you how to walk on water – but don’t hold your breath waiting. Bob, with long hair, giving a Dive briefing.
In July I was fortunate enough to yet again venture along the Great Barrier Reef north of Cairns and out into the Coral Sea. I’ve made this cruise several times on various boats including Mike Ball’s Spoilsport, the private Super Yacht Bullish, the now sadly missed Nimrod and Underwater Explorer, and this time on Taka. I have had a wonderful time on all these vessels. Professional crew, seaworthy and comfortable boats, fine food and company and extraordinary diving, with useful DIVE briefings, are standard. But on all except Bullish I had to endure SAFETY briefings, and they are often too long, tedious and worse still, sometimes inaccurate. I have a feeling that many divers at dive destinations and on dive boats around the world get as frustrated as I do. Are safety briefings necessary? Well yes, some things do need to be said, such as the particular emergency and diving procedures on individual vessels. I have just read the guidelines from Queensland Health and Safety in the Workplace, and amazingly they do NOT require many of the restrictions or rules proclaimed. Buddy diving is recommended but Solo Diving CAN take place. Not everyone wants to solo dive but if someone does there should be a simple procedure whereby a diver is able to. It is not convincing to be told it is forbidden, only to see the crew solo diving when their dive guide duties are over. So make it legitimate – it is NOT “against the law”. Spoilsport, for example, has a Solo Diving option for Experienced Divers who have their own pony bottle. Many underwater photographers prefer to solo dive – I do when not using a model – and frankly it is much safer for me to be alone with my pony bottle than buddy with a less experienced diver – who is more likely to get me into trouble than rescue me. The “Lost Buddy” procedure is another nonsense I still hear that can actually increase the risk of a dive. If you are buddy diving and lose your buddy the best response, after looking around, is not to surface but to return to the planned exit point – usually the boat. If your buddy does the same thing you will probably meet without doing multiple ascents and if not, you are safely back at the boat and alert the lookouts, and not floating around on the surface in the middle of the ocean – where most diving accidents occur! Captain Craig de Wit giving one of his sophisticated DIVE briefings for experienced regulars The buddy everyone needs, and these boats provide sterling examples of them, is the crew buddy looking out for you from the boat, with a pick-up tender available at the ready. The most common crime in briefings is still to insist on NO Reverse Profile Dives. Reverse profile dives have been given the green light since Oct. 1999, mentioning them in a briefing is out of date myth, and could lead to less-safe diving by forcing divers to go deeper than they wish on early dives in order to make, say, a 30 m dive in the afternoon. The important point is to make the right ascent from EVERY dive including ESSENTIAL (others call them “safety”) stops. QH&SW do not ban reverse profile dives. {Proceedings of the Reverse Dive Profile Workshop, Smithsonian Institution, Washington DC October 29/30 1999 – Conclusion “We find no reason for the diving communities to prohibit reverse dive profiles for no-decompression dives less than 40 msw and depth differentials less than 12 msw.”} Which brings me to the notion of being back on the boat with 50 bar remaining in your tank. This is nonsense. So answer this question. You return to the boat with 50 bar, should you now ascend the ladder or should you hang around the boat, preferably on a decompression bar or shot line and breathe up the gas? I know which is safer – it is obvious. So what I suggest is be back NEAR the boat, say within 5-10 m depending on conditions, with 50 bar, then spend time in the shallow water de-gassing and enjoying the scenery. Most of the dive sites have fish congregating under the boat that make for entertaining viewing. I also think that he term “no-decompression diving” should be dropped. I had better explain. No-decompression diving was invented to get Navy divers out of the water as soon as possible. One of the great mistakes in the evolution of sport diving was the adoption of this procedure. In the old US Navy air tables, 60 ft. for 50 minutes was a no-decompression dive. Divers could come directly to the surface at 60 ft per minute and most (Navy) divers would not get bent. 60 ft for 60 min was the no-decompression limit. You could still return directly to the surface but actually more divers would get bent. 60 ft for 70 min was a decompression dive and required a stop of 2 min at 10 ft before surfacing. This is what we are told to avoid – yet this dive was safer than the other two – even a short stop cured a multitude of sins! I learned very early on, before safety stops were invented, that every dive should be considered a decompression dive and requires a stop. I have actually heard divers being told in a briefing only to make no-decompression dives so that they can return directly to the surface: this is dangerous advice! Aboard FeBrina, Divemaster Diga discovers someone has embellished his Dive brief mud map... There is one important exception – if divers are drifting away in a current they need to get to the surface and get seen as soon as possible. A long “safety stop” could have you drifting too far from the boat to be seen, even with a safety sausage. Better still, listen to the site briefing, start the right way – into any current, and dive back to the boat! Years ago I used to charge divers if they surfaced away from the boat and required a pick up. The money went to the crewmember doing the rescuing. I had the best lookouts in the world! Incompetent divers these days think they can pop up anywhere, and get a ride back to the boat. Not smart. Unfortunately dive boats are often noisy places and I have many times had to struggle to hear briefings that were barely audible to me. My ears are partly to blame – but there are plenty like me. I want to hear the important stuff – but I do not want to hear a rerun of a basic dive course. Beginning divers are usually escorted and can have their own private briefing if necessary, so can foreign divers who do not speak English. Attention spans have their limits. Briefings have to be short to have any chance of digestion. Having a short list of the most important procedures on permanent display instead of in the briefing could save time, much as they do on aircraft safety cards and QWH&S is working on a suggested dive display right now. My suggestion for either method is simple. Make a list RANKING information in the briefing from most important to least important. This will get you thinking about what the briefing should contain. For me the most important function of the dive boat is to ensure that every passenger is aboard before the boat departs so explaining how that is controlled should be number one on the list. You will find that much of the content at the end of the list is trivial and may be safely deleted. Less is more. There is a perception among experienced International divers that diving the GBR is not very good and too restricted. But from my own experience I can state that there is excellent diving. The Great Barrier Reef is Great again, there are many large animals that invite close approach including Dwarf Minke Whales, Turtles, Cod, Sea Snakes, Maori Wrasse, Sharks and a multitude of smaller fishes and invertebrates just waiting to have their photos taken. In fact the GBR is one of the best places in the world for fish photography as fish have learned to be unafraid of divers. We can go a long way to attracting tourist divers to the GBR by letting the world know that the reef is in excellent shape and not on its way to oblivion, and that experienced divers are rewarded for their competence with an express lane into the water. Have you ever kissed a smoker? Don’t tell my wife but recently I had the opportunity to plant a smacker on a gorgeous lady’s lips – and nearly gagged. It was a shock. I missed a breath, and the gorgeousness turned to sludge. Now I think about it, Dinah was watching and had a smug grin on her face. The smoky breath reminded me of a miserable dive I once made.
Early in my diving career in the late 1960’s I had heard about bad air – but never experienced it. Then a private yacht sailed into port and after sharing a dive with the owners they offered to fill my tank, for free! I accepted, and thought no more about it until my next dive. I can still smell and taste the foul oily air, groan at the wrenching in my guts and march to the thumping headache from that stinking air. I had to abort the dive for fear of vomiting. I emptied the tank and refilled but the remains of that bad fill hung around for several dives. I became wary of bad air and tested my air fills by taking a few breaths from my regulator before every dive. Several times I have refused to dive because the air was bad. Amazingly I have been vilified because of my refusal to poison myself. “We breathe it!” “ Its fine!” my senseless, ignorant colleagues have proclaimed. “What sort of a bighead are you?” Well, I am the sort of bighead that chooses not to breathe bad air. I once made a complete fool of myself with a dive club in Lae PNG. I had been hired to run a certification course for members of the local dive club. At the first pool session I realised that the club’s portable compressor desperately needed a filter change. The air was foul. Against some resistance I insisted the filter be changed and was told to do the job myself the evening before the club cruised to Salamaua for the openwater dives. The light was not very good and when I dismantled the unfamiliar filter, which was a soggy mess of soaked carbon unable to filter anything, I unknowingly, but carelessly, lost the metal plate at one end that holds a felt pad in place. The next day we had fresh air in the tanks, but the compressor was filling at a slower and slower rate. We eventually discovered that the felt padding was being pushed into the plumbing and blocking the air delivery. The problem got fixed, but I was blamed for mucking around with their compressor. What I do not understand to this day is how they tolerated that terrible air. Not only does bad air stink and make you gag, it has bad stuff in it that can cause you serious problems diving. And the deeper you go, the more toxic the bad air becomes. These days I also take great trouble to see how the compressors are set up in any operation that I dive with. Most compressors are air cooled. They have a fan that ventilates the compressor. This fan needs space to work efficiently. When I see a compressor installed right against the hull of a boat, or wall of a dive shop, I know the compressor cannot work efficiently. If the compressor gets hot it will burn oil. Synthetic oils help but do not solve the problem. The filters will have a short life, and the service life of the compressor is reduced. But I have seen this many times. Sorry guys, but it is wrong! Many of the problems come from small portable compressors with a very short filter life – say 8 hours. That may be just 15 – 20 tank fills. Then the filter becomes useless and you are filling bad air. Compressor filters like this may need changing every day. Commercial compressors with big external driers and filters set in cool air (outside the engine room) work much better and may go one month or more before change is necessary. But they all need changing eventually. It is essential that the air intake is in a position clear of any exhausts and able to suck in clean cool fresh air. I have had to stop pumping tanks on occasion because we were close to shore and smoke from village fires was blowing right over our intake. Here is my advice. Test your air before diving and if you smell or taste any bad stuff refuse to dive and demand money back or a refill. And do not kiss people who smoke. January 2006 I had the pleasure of photographer Doug Seifert’s company a while back when we dived together for an adventurous month on MV Golden Dawn in PNG. He showed me a splendid article he had published on sharks. In the text he used the collective noun for sharks – something I did not know, and you may not have heard of either. But it is a beauty – a “SHIVER” of sharks.
The authority on collective nouns is James Lipton, whose book “An Exaltation of Larks” was first published in 1968. Doug sent me a copy – it is still in print today, published by Penguin Books. It is a fascinating read, for example if whaling ships meet they are a GAM of whalers, but the word was also used to denote a playful group of whales. POD is correct for a small group of whales (but never use a SCHOOL of whales) or for a POD of seals. Then we have a BALE of turtles, a SMACK of Jellyfish, an ARMY of herring, a SCUTTLE of crabs, and a KETTLE of fish – or perhaps a FINE KETTLE of fish when diving Papua New Guinea! Reading further I was charmed by the author’s account of his hunt for collective nouns and his invitation to contribute where no present collective noun exists. Then I realised there is no collective noun for divers! Doug and I thought of a few possibilities, then I asked diving friends for their suggestions – and now I am putting it to you. Here are some of the better suggestions, if you have a bright idea, or if any of the ones below are your favourite, please let me know. The diving world depends on us! A GURGLE of divers or COMPRESSION; DESCENT; FREE – FLOW; DELUGE; BUBBLE; FLOAT; DOWN; FIN …. of divers. I admit, I think ASYLUM of divers is totally appropriate, most landlubbers think we are crazy. I am sure you are all familiar with “a SWARM of bees”, but perhaps not so sure of the difference between swarm and school when applied to fishes. In a SCHOOL of fish the fish align themselves in roughly parallel formation with individuals slightly behind the fish in front. In a SWARM of fish individuals are randomly positioned. Strangely, research has shown that schools are actually led from the rear (as are good armies). A SHOAL means the same, I believe, as a SCHOOL, but is usually in shallow water thus looking like an area of shoaling water. Some fish school only when it is a survival advantage for them to do so and are termed “facultative” schoolers. Other fish school compulsively – even if only two fish are together they will line up with one slightly behind – and these are known as “obligatory” schoolers. At other times fish may group together in “aggregations” rather than schools or swarms – hammerheads and mating groupers come to mind. Since we are all about words today I will finish with the difference between fish and fishes. Fish refers to one fish, or to more than one fish when all the fish are of the SAME species. Fishes is the term used when more than one fish of DIFFERENT species are referred to. At least this is how all the Ichthyologists that I have ever met refer to them, and how the Oxford English Dictionary used to refer to them. But it has all changed. I know this because I was asked to write a chapter in a book on Oceans to be called “The World of Fish”. I complained and said it should be called “The World of Fishes”. They insisted, so I wrote to the OED, expecting confirmation. Alas, OED told me, they try not to be proscriptive (and say how a word should be used), they instead are descriptive, and say how a word is generally being used today. According to them, people just don’t use “fishes” any more; they use “fish” for everything. Unless you belong to PETA in which case you use “Sea Kitten” – but that is another story. In other words they have given in to all the phallcephalites using the word incorrectly! Don’t let it be you! |
AuthorBob Halstead usually has Deep Thoughts on all manner of dive related activity. Have a dive in and read some of his best previously-published articles. ArchivesCategories
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