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Who looks out for you when you have diving equipment problems? Diver does. In a new quarterly series, John Bantin fields your queries about gear, and calls on the suppliers for help where appropriate. If you have a problem with kit, let him know.
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Failure to shave may explain some leaks from men's masks, but for women there are usually other explanations. |
Why does my mask always seem to be leaking water?
If your mask leaks, you will be able to see a trail of small bubbles when you hold your breath and look upwards. This might be because the junction between glass and frame is getting tired, in which case it's time to get a new mask.
It is more likely that it's your face that's leaking. I hear stories about men shaving off beards and moustaches and applying silicone grease to their faces, but I have both a beard and moustache and do not suffer from leaks.
A possible cause is that you have tightened the strap so much that the mask frame is distorted.
More likely, you unknowingly exhale slightly through your nose during normal breathing, and water then finds its way back in as the air forces its way past the skirt to escape the mask.
My friend and I are intermediate divers with some experience but cannot settle on the correct way to wear an octopus.
I say that it is for the primary use of your buddy or another diver in distress and is more convenient to wear from the left side of the body, allowing for an easier face-to-face ascent. He says that it's primarily for yourself, so should be worn on the right where it's easier for you to use. Who is right?
Mick Smith
One training agency declares that an octopus should be rigged to the right and clipped in the area of the chest.
I maintain that it is intended for use by someone other than the wearer, so it makes sense to rig one that has a standard-length hose on the left, as you rightly say.
The octopus is not primarily for your use because a reg malfunction, though rare, usually involves the first stage. Second-stage problems tend to be inconvenient or uncomfortable, rather than life-threatening. Your own octopus would of course be useless in your own out-of-air situation.
Rigging an octopus on a longer hose makes sharing easier and largely avoids problems caused by left- or right-handed rigging. You could loop it under your right arm and around your shoulder or under an elastic strap on your tank. What matters most is that you know exactly where it is and can deploy it at short notice.
There's redundancy in computers, and then there's plain overdoing it! |
Should divers generally rely on their diving computers or also use a watch and depth-gauge as back-up?
Jen B
I always dive with at least two computers rather than a computer, watch and depth-gauge. Why? Because it is conceivable that a dive computer might let you down, and although a watch and depth gauge may get you back to the surface safely, you will then need to wait 24 hours before diving with another (functioning) computer.
A second computer will not only give you back-up for the first dive, but will be up to speed with your deco requirements for the following dive.
Electronics are more reliable than mechanical solutions and also cheaper. My Rolex is a nice piece of jewellery but I wouldn't rely on it nowadays to tell the time! The same goes for pressure gauges, mechanical depth gauges and other clockwork.
Split fins can be very good but they're not inherently superior. |
Are split fins worth buying?
Derek Young
To say that split fins were better than the conventional variety would be a sweeping generalisation.
Some years ago DIVER tested a large number of fins using a cross-section of divers and underwater speedometers made and supplied to us by Pete McCarthy, inventor of the Nature's Wing split fin concept.
We found that some fins were better than others but there was no evidence to suggest that all split fins were better than all conventional fins.
There are a lot of different good fin designs available and, like a pair of shoes, what suits you may suit another diver less well. A fit diver will do well with almost any style of fin.
Can I get a filter to give me good colour with my digital camera under water?
Digital cameras may promise instant gratification, but light is still light, however it is recorded, and water absorbs light selectively, starting with colours of long wavelength such as reds and yellows.
A filter does what it says it does - it filters out colour. So a red filter does not make a scene redder, it makes it less cyan (blue). Under water, as we go deeper, the reds get absorbed and eventually only blue light penetrates the depths.
You can add a filter to filter out this blue light, but if there is no other colour light present, you will be left with no light at all with which to take photographs.
If you stay in the shallows, where there might be a surplus of blue light in comparison to the warmer colours, you can use a filter to redress the balance. This filter will look a sort of orange colour (Kodak Wratten No 85).
There is a company now marketing Magic Filters. Don't be misled - there is no magic. A filter will be effective only where light of the colour that it passes exists. A Magic Filter may be of exactly the right colour to work with the light typically found in sunlit shallow water at around 10m or less.
The other thing you can do is shoot RAW files and adjust the colour using colour temperature and tint controls on your PC after shooting - but that's another story.
A top-hat will make it easier to disconnect your drysuit direct-feed hose, and as small items in dive shops go, it's cheap |
I experience great difficulty in disconnecting my drysuit direct-feed hose when wearing dry gloves. This can lead to embarrassing delays while attempting to get back in the club's RIB. Are there any simple solutions?
Yes, you can fit a plastic addition to the business end of the hose. This is often referred to as a top-hat. It costs only a small amount and your local dive shop can supply you with one.
The device simply pushes over the existing pull-back sleeve. Some drysuit valve manufacturers supply their hoses already fitted. They simply provide a bigger surface to grip when wearing thick gloves.
What maximum lift do I need in a BC?
We often see BCs (mainly wings) that claim an inordinate amount of maximum lift, but why do you need it?
A BC is used to provide neutral buoyancy when submerged, and as an aid to flotation at the surface.
Assuming that you are neutrally buoyant at the start of your dive, you will not need much to account for lost buoyancy in your wetsuit at depth. If your drysuit fails, you will not need much lift in your BC to compensate for that lost buoyancy, and this holds true even if you are diving with multiple tanks. You can abandon side-slung tanks if need be, and the weight of the gas in full twins is unlikely to be much more than 6kg.
At the surface, a lot of lift can be useful but not if most of the buoyancy chamber is above the surface of the water, where it contributes nothing to buoyancy. Many conventional BCs give as much surface support as some massive wings at this time, as nearly all their lift is under water and counts.
So how much lift do you need? No competent diver should need more than 20kg of maximum lift, however many tanks are used. Avoid being over-weighted to begin with.
A good rule-of-thumb is that you need no more maximum lift than you have weight on your belt.
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KEEP YOUR QUERIES COMING
Submit them, marked "Kit Q&A":
by letter, addressed to DIVER, or by fax on 020 8943 4312
by e-mail by john@divermag.co.uk
on DIVERNET's Equipment Talk page. This can also bring you rapid responses from other readers (though these should of course be treated with caution).
We regret that questions cannot be answered on the telephone or, generally speaking, replied to individually.
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