There are plenty useful informtaion for divers on oue website, such as: *Sea sickness medication The problem with sea-sickness medication is that some of these tablets may make you drowsy and may therefore predispose you to nitrogen narcosis. It is strongly advisable to find the medication which best suits your body. First, you should purchase a type recommended by your local pharmacist (e.g. Stugeron), and take a test dose at a time when you are not driving or diving. If you become drowsy, you will know the medication does not suit you, and you must then try another type. This procedure should be repeated until you find one which does not make you drowsy. It is important to note that the one which suits you best may not suit your buddy at all. This is nothing to worry about and is due to differing body metabolism. Your initial dives on this medication should be shallow and depth should be gradually increased over subsequent dives in order to minimise the possibility of adverse effects on a deep dive. Beware of the possible additive effects of this medication with prolonged use. If any drowsiness is experienced, you should not take a dose on that day. At the start of a new diving season, prior to diving, it is advisable to retest yourself in this way to ensure that your chosen medication still suits you *Ear clearing difficulty If you have problems clearing your ears on descent, then you are having difficulty inflating your middle ear via the Eustachian tube which connects it to the back of the nose. There are several things you can do to help make it easier to clear your ears. Firstly, practice inflating your ears several times a day for three to four days before you intend diving but don`t do this if you have a cold as pushing infected mucus into the middle ear is not a good idea. Regular use tends to open up the Eustachian tubes. Next, when in the water, start inflation from the surface downwards and for the first few metres with each breath. Never wait until there is a pressure on your ears and, if you can`t clear or if there is pain, go back up until the pain and pressure has gone and try again. *Dysbaric osteonecrosis There are a number of causes of bone necrosis but exposure to hyperbaric conditions is the usual reason when it occurs in someone who dives or has dived in the past. Until recently it was though to be an occupational illness occurring in only professional divers and caisson workers. However in the last few years the members of the UKSDMC have become aware of cases occurring in amateur divers. *Diabetes and diving study Diabetes mellitus is present in about 3% (2.5% known, 0.5% unknown) of the UK population. Hypoglycaemia (low blood sugar) may be treated by the oral administration of glucose (either in solid or liquid form) if the patient is conscious, or by the intramuscular injection of glucagon. It is this risk of hypoglycaemia occurring in a situation in which administration of glucose or glucagon is delayed, thus leading to unconsciousness and death in the diver with DM. There is also the risk to the diving buddy from having to rescue a hypoglycaemic diver from under the water or on the surface. Our study takes the form of a questionnaire which is administered, on an annual basis, to those diabetic divers who wish to dive. It is unique because it is the only study, to our knowledge, currently being conducted where data is being gathered from divers doing ``real life`` diving as opposed to controlled chamber dives or monitored sea dives over a one or two week period. Although the study has over 200 divers on the data base (18% females and 82% males), this is less than the number expected, assuming the numbers given above, though one has to take into account the effect of the pre 1991 rulings preventing divers with DM to dive in the past.

We aim to highlight recent research concentrating on fitness to dive issues, and decompression risk assessment. Here is an example of reseacrh results: ``Provocation testing in asthmatics The new guidelines are almost ready for publication from the British Thoracic Society aiming to provide expert guidance on assessing individuals with lung disease for fitness to dive. Worldwide there is considerable variation in recommendations, with some countries banning asthmatics outright. Others insist on provocation testing. A recent paper assessed the prevalence of bronchoconstriction following the inhalation of carbachol. They studied 76 subjects who had all been passed fit to dive by their personal physician. All had a history of previous asthma which was now inactive, or currently well controlled allergic asthma or rhinitis. The results are difficult to interpret. Half of all subjects developed bronchoconstriction following the provocation test, but there was no difference in the degree of bronchoconstriction between the three groups (remote asthma, allergic rhinitis without bronchospasm, current asthma). Unfortunately there was no normal group to allow comparison. Baseline spirometry was similar in subjects with and without a positive response to carbachol, including FEV1, FVC, FEV1/FVC ratios and plethysmographic measurement of airway resistance. There was no difference in terms of age or basic physical characteristics such as height. The authors conclude that subjects with a positive response should not be allowed to dive because of the risk of pulmonary barotrauma. Overall there is little supporting evidence to perform inhalational provocation testing in all asthmatics before diving. It will be interesting to see what the BTS guidelines summarise from the limited evidence available, but it is unlikely to be substantially different from the current UKSDMC medical standard. Like many areas of diving medicine there are many strongly held opinions and only limited supporting data. The way forward here would be to prospectively collect information by performing a careful case control study, although given the current estimate of decompression risk (approx 0.0034% of dives) this would require to be a huge study and as such it is unlikely to be performed.`` You will find more on our website.