The liveliest letters from the DIVER mailbag...
After reading an article on Divernet about mantis shrimps, I wanted to let you know just how powerful and potentially dangerous these little critters can be.
A few years ago, I set up a large marine aquarium in my front room. As I wasn't a diver at the time, I wanted to get close to the wonderful creatures that fill the warmer waters of the world.
I spent a lot on the outfit and had a large stock of fish, including angelfish and clownfish, with a couple of sea apples and some living coral (which was, as I know now, a very bad thing to have, with the stock in the wild dwindling).
I always used the same supplier and he often told me that if I was buying living rock and coral, once I had had it in the tank for a couple of days I should keep my eye out for mantis shrimps. These, he said, could hide in the rock and come out once in a nicer environment. I was told that they could be "very costly".
I half-listened to what he said about the powerful "anvil" they used to kill prey. I was thinking "love to see one of these and watch it do its thing!".
About two months later, I found out how powerful mantis shrimps are. I spotted one and watched it for a while. It came up next to the side of the tank and suddenly unleashed its anvil, striking the glass. Alarm bells started to ring and I remembered what the fish man had said. The noise was amazing, but I knew the shrimp had to go.
I got my net out and had opened the top ready to fish it out when it let loose another strike on the glass. This time, it struck it so hard that I was aware that my feet were getting wet. Yes, that's right, it had actually broken the glass! Water was going everywhere, but all I could think of was my investment disappearing into the carpet.
I fished the shrimp out, put it into a plastic spawning container and rapidly patched the glass with a sheet of glass and some silicon. Fortunately, I saved the fish, though some didn't look too well for a few weeks.
My point is, if one of these things can do the damage it did to fairly thick aquarium glass, could it not do the same to mask glass? It's about the same thickness and is toughened in a similar manner. Maybe a little more caution should be taken and a little more respect given to these small but powerful little things!
Richard Smith, Maidstone, Kent
I agree with John Liddiard's comments in What-ever Happened to Nitrox? (May). I too feel it is unnecessary to make new valves for nitrox tanks. It seems like a nice little earner for somebody.
As a single parent, my spending money is limited. My kit is regularly O2-cleaned and serviced, but now it seems I must buy different equipment if I wish to continue with nitrox.
If it hadn't been for nitrox, I wouldn't be here now. I was lucky three years ago to have an 80% mix loitering in my garage, as this elixir of life kept my body from deteriorating further during a long taxi journey to Poole's hyperbaric centre, where they were waiting to treat me for a severe spinal embolism.
My treatment lasted two weeks, and it took 12 sessions in the pot to bring my body and mind back to normality. Later I was diagnosed with a very large ASD (atrial septal defect) which has since been repaired.
I like diving on nitrox. I feel I have a clearer head while I'm diving and I feel less tired after a weekend's jolly to the coast. I wonder how many people will have to go back to simply having isotonic drinks to get them home when they find they cannot afford to change their kit to EN 144-3's requirements.
Belinda Gadsby, Bristol
After reading the news item Holiday Divers Urged to Take a Break From Repetitive Dives (June) I was left wondering whether DAN was saying the right thing in the right way. If you make repetitive dives for a week and rely on your computer, I agree with what it is saying, but if you plan your dives properly and then use your computer as an aid, I think I disagree.
I have just come back from a two-week diving holiday in the Maldives, where I completed 25 dives. These varied from 30m-plus in the morning to progressively shallower dives throughout the day.
I was probably the only person who planned his dives using tables, wrote the info down on a slate (which came down on the dive), set time and depth limits on a separate watch alarm and then doubled my time on the deco stop. Most other divers hired the club's dive computers, never planned their dives with tables and were blindly led by the divemasters who, as it happens, were very good.
The worrying thing was that most people had that mentality of "I'm on holiday and nothing will happen to me".
Fortunately one diver asked the divemaster what the flashing symbol on his hired computer was - he then sat the next dive out as he had gone into deco time and missed his extra stop. This was because all he had to rely on was a dive computer that he didn't know how to read!
OK, there were no other incidents. But your safety is your own responsibility and the buck stops with you to plan the dives properly and greatly reduce the risk of decompression sickness.
Richard Wingett, Maidstone,Kent
Having seen the recent TV ads referring to the use of the OK signal and its interpretation in Brazil, can any readers tell me what signal Brazilian divers give to their buddies to signal OK?
Bill Tate, Peterborough, Cambs
We put that question to Vivian Szterling of Atlantis Divers in Natal, Brazil: We do recognise the international OK hand gesture and use it for underwater communication. But in the "street language" it is not used, as it is offensive. On land we use the thumbs-up as OK.
I dive with PADI qualifications. After becoming hooked on a warmwater try-dive, I returned to the UK to qualify under what I thought was some first-class tuition. Week after week I dive to enjoy the thrill of being under water, but this enjoyment is tempered by the arrogance of a sadly large section of the dive community.
Returning to the same inland dive site each week, I can handle. Diving in freezing cold, murky water I can handle. But I am fed up with the miserable bickering between divers.
My girlfriend is new to diving. On her first dive after qualifying, at an inland site, she unfortunately experienced a mild panic attack on descent. Her instructor brought her safely to the surface, where she was notably upset, more through frustration than through fear of a repeat incident.
While making her way out of the water, she was stared down by another diver who, without breaking eye contact with her, said to his buddy: "F****** PADI trainees, shouldn't be allowed in the water."
A nice way to refer to an obviously distressed diver, and since then her confidence has been shattered and she hasn't enjoyed diving, to the point of nearly quitting.
I don't mean this as a BSAC- or PADI-bashing session, as miserable people exist regardless of organisational membership. Which brings me to a recent experience at Capernwray. From the queue to get in, people were friendly. If our group were being loud, people laughed with us rather than looking at us like lepers. If we were struggling with heavy kit, people would lend an arm to lean on. If you smiled at someone, you got a smile back.
The upshot of all this was a thoroughly enjoyable and stress-free diving experience. I had some of my best inland diving and, more importantly, my girlfriend was able to dive with more confidence, skill and enjoyment than ever before. She is now relishing her next dive.
Diving shouldn't be taken lightly, but leave the in-fighting to the diving organisations and let's start enjoying ourselves. I don't get up at 5am on a cold Sunday morning to be miserable all day, so we're not going to let you get us down anymore. You go ahead and be miserable - go on, you know who you are.
Many thanks to the team at Capernwray for restoring the faith.
Matt Edwards, Northampton
I have a guilty secret and it's time I got it off my chest. I seek out the company of strangers. I spend my weekends anxiously waiting in grotty car parks for individuals and couples who share the same desires as me. A specialist website and a furtive phone call when the wife is in the kitchen, and I'm set up for the early-morning rendezvous.
People who don't indulge in my hidden pleasures are baffled - they say it's dangerous, I can't know what I'm getting into, that I'm putting my health at risk and that surely it's illegal or at least frowned upon. They're simply content to keep on with the same old partner they've had for ages.
"Yes it's a bit samey," they say, "but at least there are no unwelcome surprises in store." That's not for me.
They don't know the thrill of being with someone new. The excitement of experiencing a new technique, putting your trust in someone whose surname you don't know, from being with like-minded and broadminded people who simply get off on the buzz of doing it with strangers.
I would recommend it to any of you out there who feel a bit jaded with your existing partner - find that website, make the contact, don't be shy and jump right in.
Everyone should try diving with new buddies!
Nigel Pierce, Market Harborough, Leics
Following recent items in Diver concerning taking diving equipment on aircraft. I would like to share my experiences.
We travelled to Malta regularly with a leading airline. Maximum personal allowance for luggage was 20kg plus 10kg gratuitous allowance for diving kit. Anything over 30kg was subject to a duty of approx £4 per kg.
For the past three years we encountered problems at the check-in desk when the diving allowance had not been annotated on the documentation by the airline's booking staff.
Last year I checked three times with the airline's customer services department before flying and was assured that the extra allowance was on its records. Yet again, it wasn't. We had to hold the queue up for half an hour until the problem was resolved.
Last month three of us travelled to L'Estartit in Spain with budget airline Ryanair and were thoroughly impressed with the service.
On booking we told the staff that diving equipment would be carried. As this is classed as "sports equipment" and pre-booked, we were charged £5 per head for this service and still allowed our personal baggage allowance. There was no hassle at the check-in desk, as our confirmation letter showed the allowances.
If low-cost airlines can provide this service, surely the major ones can - or are they putting profits before people? Airlines are now charging £10 for in-flight meals, charging for hotel transfers, and it wouldn't hurt too much for them to follow Ryanair's example.
Brian Athey, Ashington, Northumberland
Turn to this month's Travelling Light feature.
I was interested to read Kevin Gurr's response to John Bantin's review of his VR2 computer (VR2 Controversy, Off-Gassing, June). I would offer one plea to Kevin - make the deep stops optional, so that users can choose whether or not to use the computer's method, their own or none at all.
I own a VR3 and its mandatory deep stops are the main reason I don't use it.
An example arises when diving Cow Spring in North Florida, with a maximum depth of 33m or so. The VR3 gives you a deep stop at 10m, which just happens to be right in the middle of the entrance restriction.
That makes it somewhat inconvenient for anyone else who wants to get in or out of the cave during those two minutes.
Another example was when diving as part of a team on a new wreck in 87m off Brittany.
I was hoping to use the VR3 as my personal backup to the tables with which we were diving, but as our planned deep stops did not happen to agree with the VR3's, it was effectively useless for this purpose and was therefore left on the boat.
There's nothing to stop users planning and executing their own deep stops. Unlike most decompression, deep stops can easily be worked out in your head.
A computer such as the VR3 is catering specifically to the technical diver who will be trained (a condition of purchase) and therefore capable of planning and executing deep stops themselves.
There are always going to be occasional specific situations where the user may want not to use the computer's deep-stop method. In your next revision of the software, Kevin, why not make them optional? Please?
Andrew Pitkin, Southampton
Fresh from an Open Water course, my holiday to Malaysia a few days later offered many opportunities to dive. It was a real eye-opener, and underlined for me that you can't rely on third-party checks on equipment.
At one dive centre I was handed a regulator assembly only to find that when I flexed the hoses at the first-stage connections, the inner could almost be seen, as the rubber had perished. There was also a BC with a glued-on patch that was working loose.
Replacements were supplied immediately when I pointed this out, with an embarrassed look from the divemaster. This was a tainted part of an otherwise excellent operation.
An incident later highlighted how complacency or lack of regular checking could lead to disaster. Two experienced divers on their second dive as a buddy pair did not appear to be close enough to be able to help each other in an emergency.
I heard a loud crack and air started to flood from the first stage of one of them. There was nothing this diver could do in the circumstances except a CESA [controlled emergency swimming ascent], which fortunately proved effective from around 10m.
The buddy was too far away even to hear the bang, and only some time later caught my attention and understood from my hand signals what had happened.
The dive centre later claimed that new O-rings were used every time the cylinders were filled. Oxygen was supplied but the quantity was so limited that, had another emergency occurred, there may not have been enough.
The holiday was an excellent experience but a big learning curve.
Steve Jones, Lowestoft
In his lead letter in May, Wind Blows Both Ways at Portland, Dave Selvage waxes lyrical about the proposal to site wind turbines in Portland Harbour. He sees this as a sensible and sustainable solution to future power requirements and a useful contribution to the UK's commitments under the Kyoto Treaty.
As a professional engineer I also encounter wind turbines. It is now almost impossible to avoid these monstrosities as they pop up across our country and most neighbouring European states in the name of sustainable energy.
Well, Mr Selvage, you may like them, but make no mistake, these machines are only about money, not environmental concerns.
The average field of wind turbines creates no more power than a pea-sized nuclear reactor and they are not cost-free in respect of the environment or consumption of resources.
They do attract government subsidies in various states and as such they are an attractive cash crop for many engineering enterprises, especially oil companies, which are seeing their petrol business diminish as cars become more efficient.
It is interesting that the Kyoto agreement is cited as a laudable document in support of this proposal and the banning of diving on HMS Hood. Isn't this the same treaty that the USA, despite being one of its major architects, has refused to honour?
Come on, Mr Selvage, if we suffer misinformation from the authorities, let's at least be truthful with one another.
PS, I haven't seen the Great Barrier Reef yet.
Philip Pope, Woodham Ferrers, Essex
Those who grew up with, and were inspired by, the television series The Undersea World of Jacques Cousteau, may be interested in a website called www.tvshowsondvd.com. This enables you to vote for programmes you would like to be released on DVD.
The site requires you to register but it's free of charge.
I am sure many thousands of divers around the world would be interested in buying copies if it were ever released. I wonder if the programmes would be as captivating now as they were back then.
Richard Clarke, Hele, Devon