Dr Jules Eden, dive medicine specialist and founder of e-med, answers divers' questions - as published in Sport Diver magazine:
Q - My question is simply that I am about to go to the Maldives where I will do some diving. I have my PADI and Advanced PADI qualifications, but have not dived for about 4 or 5 years. I am 51 years old and generally fit, other than being a little overweight. Do you have any specific advice about whether it is appropriate for me to go diving and if so, whether there any matters or precautions I should bear in mind? Thank you.
A - Diving in the Maldives is generally fairly untaxing, although sometimes the currents can be strong and depths can be considerable. It's worth training up to use Nitrox if it's available. Obesity will often naturally correlate with reduced fitness, and there is some concern about it increasing the risk of decompression illness, but only in extreme cases will it be too risky to dive at all. So other than a little slimming down and effort in maximising your aerobic exercise capacity, there's little you need to worry about. There are a few general tips to remember:
keep well hydrated (diving causes a diuresis and in warm climates you need to be chugging on fluids constantly)
slap on the suncream
avoid excessive alcohol intake
before each dive, do a quickhead-to-toe check to ensure you have no ear/nose/sinus congestion, that your chest is clear, and your abdomen free of diarrhoea or other imminent activity.
Q - Doc, I'm getting fed up with my dive club making jokes about how bad my gas consumption is. I admit I'm not the slimmest card in the pack but I've been trying to exercise more, going to the gym and swimming twice a week. My girlfriend does yoga and thinks I should try it as she reckons it makes your lungs bigger. I always thought it was a bit weird but I'll give it a go if it makes me less of an air pig. Is this true or would I be wasting my time?
A - Yoga has come a long way from being a vaguely disconcerting habit of quirky hippies in the herbaceous fug of the 70ís. Itís now so uber-trendy that you canít bend over backwards for Om ornaments and Buddha bling. Myriad variations on its central theme (the ďbringing together of parts in order to create a unionĒ Ė no sniggering at the back there) have resulted in splinter forms springing up everywhere. There are now specific scuba-orientated yoga trips the world over, from the Bahamas to the Red Sea. So how can gaining inner peace benefit the humble diver?
Letís start with the physical aspects. The common Western perception of yoga is that itís all about impossible contortions and ludicrous postures. Modern society has made us stiff (apparently) and this is why we find the poses so tough. For a diver though, the essential elements of yoga can significantly reduce the likelihood of injury. Specific exercises can improve core stability, working on the lower back to protect it from the trauma of twinsets and weightbelts. Targetting the legs and hips can improve finning (both technique and stamina), and make that long slippery trip in full kit from the car park to the waterís edge a joy. Or at least less of an ordeal. Stretches before and after diving will keep the muscles going for longer, especially on those long liveaboards, and, by improving flexibility, can help the burgeoning wreck or cave diver in and out of awkward tight spaces. More generally, the breathing exercises that are fundamental to yoga are also ideal for improving lung capacity and encouraging effective steady breathing during hard exertion. Ultimately this will extend bottom times and reduce feelings of panic underwater, which we all want, donít we.
And what of the more, ah, spiritual aspects to the ancient Yogic arts? Well the original goal of yoga was to intertwine the body and the mind so that the two could become one. Iím not saying weíre going to find the answer to Life, the Universe and Everything underwater (itís 42, in case youíd forgotten), but there are parallels between this aspiration and many diversí urge to find the solitude and peace they miss on dry land. Visualisation techniques in yoga are often practised by freedivers, and can help prepare any diver for challenging or particularly strenuous dives.
So before belittling the posh toffs of yogaland too much itís worth giving the practice a chance to make us better divers. Particular poses Iíd suggest include the Sun Salutation at Stoney, or the Wind Relieving one at WraysburyÖ
Q - I am attending the pool session tomorrow for my OWC but have a few issues.
I answered 'yes' on three questions from my medical questionnaire. Firstly regarding my sinus problem that resulted in sinusitis quite a few times, which I was told is caused by a deviation of septum. Had problems with it in the past, at the moment it seems OK. My nose seems clear and the Eustachian tube seems clear. Second 'yes' was regarding a minor back problem that seems to occur only after I lift heavy weight. The third issue is recreational use of drugs. I occasionally use cannabis. Last time I have used it was a week ago. I do not drink alcohol or smoke cigarettes, and when using cannabis I either vaporize it or take it orally. I am fully aware to avoid using it long before any diving activity as it could put at risk my safety and safety of the others.
I would be most grateful for your reply and opinion regarding my attendance of the pool session tomorrow. If not, I can easily reschedule it.
A - Lets go from the top. If you can clear your sinuses on aeroplanes, then you should be fine diving. A really deviated septum will make the air you blow up your noses to equalize your ears asymmetric. This may result in over blowing one middle ear and not enough in the other. Result…a weird feeling as you descend. So that needs checking before the open water dives, but if it seems OK, then it will probably be OK.
Your back could be an issue if you cannot lift a tank. If it "goes out" so to speak then you don't want spasms underwater. You have to test it really and know your limits. So try with rucksack home from the shops with a load of your favourite things. 20 kilos of skunk, perhaps. If you can do that then you have no fears on the big day.
Recreational drugs. In my day that used to be crystal meth, hearts and some odd stuff a PhD chemist used to call Crazy Ivan. But trends change with you young things nowadays. Cannabis has 3 downsides. Psychosis, growing breasts if you are a bloke and irritating conversation for those who have not partaken. I would suggest you don't have any for a good 12-24 hours before you go for a dive. After all it's dangerous to giggle through a reg, and fish don't sell Snickers bars.
Q - I understand you are currently shown as one of the medical referees on the BSAC/PADI system. My membership is due for renewal, and there are three questions on the certificate on which I have to ask for advice.
I think a short 'pen-picture' of me might help! I am 54 years old, and I am a serving police officer. I am 5'-8" tall and weigh 16 stones. I returned to diving some 3 years ago following the death of my wife, and have so far been passed fit to dive by my own (non-diving) GP. In addition to diving I also swim, enjoy hill-walking and go to the gym on a (fairly) regular basis. I am a non-smoker and my alcohol intake averages about two units per week. Other than my weight, I consider myself to be reasonably fit. The points to cover are as follows:-
1. High blood pressure. My wife died of metastatic breast cancer in 1998. In the terminal phase I was quite stressed and my GP became unhappy with my blood pressure - which was running at about 150/90. He initially prescribed 'Atenolol', but after my wife's death, and when I starting diving this was switched to 'Innovace'. With my GPs assistance I was weaned off this some 12 months ago. My last BP check (April 01) showed it to be 129/75.
2. I have suffered a pneumothorax - 27 years ago. This was as a result of being immobilised as a result of a car accident. It is thought that a blood-clot developed in my calf, detached and ended up in my lung. I was treated with 'Warfarin' for six months. However, I resumed (Army) sport diving whilst still on medication, and have never suffered any ill-effect.
3. I am a migraine sufferer, and have been so since I was sixteen. These are normally of short duration (3-4 hours) and generally respond well to commercial analgesics. The attacks appear to be mainly stress-related, and occur on average once per month. I cannot recall having an attack post-dive.
I would value your assessment regarding my fitness to dive. Should you wish to see me, I can get to your practice as I live at Crawley, in Sussex.
A - Well, to start at the top with the blood pressure, it all seems under control now without medication so no worries there. Get it checked by your doctor on a yearly basis to make sure it stays below 160/100, which is the recommended upper limit for sport divers. Any higher and its back on the medication for you.
As for the pneumothorax, the rules are that you are fine as well. As yours was as a result of a car crash then you are fine to dive sooner than someone whose lungs pop for no other reason than that they are a tall young smoker. The warfarin is an issue if you are still on it. The old rules were that you were banned from diving if you took this blood thinning medication. However it is accepted now that the reason not to dive, that of a potential bleed into your spinal cord on a bend provoking dive can be safely ruled out by a max depth of 20 metres means that you can still at least get wet.
Lastly the migraines. This is an odd scenario. There are those that feel that divers who suffer recurrent migraines shouldn't go underwater ever again. Other docs feel this is a tad Victorian. I personally would advise that if they are mild and you know the provoking factors then all is fine, but severe and regular forget it, as the last thing your buddy wants to see is you flopping around like a hemiplegic starfish as half of you paralyses and sees big areas of blindness in their field of vision.
So all should be well for you to continue the sport. My condolences for your life situation too, but a key factor in the rehabilitation of anyone after such a tragedy is the "getting back to normal". Diving helps in this, so do please go as soon as you can.
Q - I have a problem with my air consumption when diving.
I am 63 years old and learnt to dive 3 1/2 years ago. I have since logged over 100 dives in both UK and tropical waters and achieved Master Scuba Diver rating. I am 5'6" tall and weigh 83kgs. I keep fit by going to the gym most days where I have a 40min programme of mixed aerobic and weight exercises.
I am invariably the first up from a dive whilst my buddy ( who is younger, but considerably more overweight than me) always has a lot of air left.
This makes me feel that I am spoiling his dive somewhat, although he is always happy to dive with me. On a recent 30m dive in the Channel my air consumption was approx. 25ltrs/min.
I feel comfortable and safe when I dive and feel well within my capabilities.
Is this a problem that I just have to accept, or is there anything that I can do to reduce my air consumption?
A - This is the real 6 million dollar question for all the guzzlers out there. From your mail it seems that you are aerobically fit, you don't smoke and you are relaxed when you dive. These are the normal things which can increase our air consumption.
I have seen in a lot of people, and I suppose in some of the dives I have done, that a perception of feeling calm is not quite the case and the reality is that you have a frisson of anxiety which comes across in an increased respiration rate and consequently an empty tank.
I experienced this once where I got hit with vertigo quite badly, and saw the whole seabed spinning at 78 rpm. When it had passed after a few minutes I noticed that I had drained 50 bar in that little time underwater. So a lesson here is that we may feel calm but in reality we could be a lot calmer.
Some divers have told me that they practise relaxation training to good effect to lower air consumption. This is worth a try, and if you learned the arts of yoga or self hypnosis as a means to this end then it could work well.
If all this fails and despite lowering your metabolic rate to that of a Buddhist priest you still get through a tank in 25 minutes then its twinset time for you.
Other tricks are to find a buddy with a similar rate of consumption so you don't feel the angst of having to surface your partner when they still are on 100 bar, and finally remember that you shouldn't let your air get below 50 bar as there is often a temptation to drain your tank to eke out the last few minutes underwater.
Other diving tricks that I can't recommend are skip breathing and purposeful breath holding as the chances of lung damage are too high.
I'm sure there are other ways of reducing air consumption from your tank, including trying a Nitrox rebreather course, so if any other divers would like to tell me how they stopped guzzling and became a more efficient user of their air I will pass the advice on in the next issue.