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During the Middle Ages, Merino wool was so prized that it was made illegal, on pain of death, to export a Merino sheep from Spain, lest it break the kingdom's dominance of the wool trade. The intensive grazing of Merino sheep stocks in those years gave Spain the stark landscape it has today.
Nowadays the finest Merino flocks are found in New Zealand, where a pristine Alpine landscape of the sort you saw in Lord of the Rings results in an elite type of sheep - and the Spanish are still complaining about it!
We all know about the efficacy of wool for keeping you warm. Merino wool has particularly fine fibres and its complex natural structure, with its hydrophobic outer scales and hydrophilic inner cells, keep both the sheep and those wearing garments made from their wool extremely warm and dry.
New Zealand Merino sheep are said to have a fleece with extra-long hollow fibres, resulting in a particularly soft and strong end product.
What does all this have to do with diving? John Gordon, doyen of diving suit designers, has a son who lives in New Zealand. Ever thinking of ways to improve his designs' thermal efficiency, he tried Merino wool as a suit-lining and found that it out-performed in many ways the more often used synthetic materials made from petro-chemical products.
waterlogged layer
Water is the insulator in a wetsuit. The Pinnacle Polar has a Merino wool lining that absorbs and retains water entering the suit. This creates a waterlogged layer between your skin and the suit which can add up to 3mm of extra insulation. On top of that, the wool is exothermic, in that it produces heat as it gets wet.
The Pinnacle Polar is a one-piece suit made with a mix of 5mm and 7mm neoprene. It has a front-entry cross-chest zip. Long zips at the ankles allow the neoprene outer layer to cover the soft latex seals but let a big foot like mine pass through. The seals deter water from flushing through.
The cuffs of the sleeves have O-ring-type seals at the ends and a chimney seal in the sleeve for the same reason. Underneath the main zip is a soft 3mm shoulder cape that you wriggle into place once the suit is pulled up to the chest. Then, with the hood pulled up over the head from behind, the main zip is closed.
There is a knack to this. This suit is cut with pre-bent arms and legs, and gussets on the inner curve of the elbows and knees allow for a degree of mobility otherwise denied. Hood up and zipped in, like a medieval knight at a jousting tournament, I felt well-insulated from the outside world.
Let's be clear - this suit does not have a fluffy or towelling-like lining, because the Merino wool is knitted into a tough cloth. Nor is the Pinnacle Polar a drysuit. Although it has internal seals within the arms and soft latex seals at the ankles to prevent flushing, it needs some water within it to be fully thermally efficient, as with any wetsuit.
clammed shut
The knit of the Merino lining helps to reduce the movement of the water inside the suit, and because the insulating layer of this wetsuit is water, it is incompressible and unaffected by depth.
So although the neoprene of the outer layer crushes and loses its insulating properties (it can halve its thickness between the surface and 40m) as all neoprene does, the 3mm of water held in the lining between you and the suit's outer layer does not.
I am told that in tests carried out by the British Textile Technology Group, Merino wool offered a serious increase in thermal efficiency over synthetic linings.
So are there any disadvantages to having a soggy lining to your wetsuit? It doesn't feel itchy against the skin because the wool is so fine, and because of its ability to draw water away from its surface it doesn't feel damp when you next put it on. In fact, it doesn't really feel soggy at all.
It's claimed that the uneven surface structure helps prevent the build-up of odour-causing bacteria, and the natural crimp seems to make it resilient to Velcro-attack too. So, no disadvantages as far as I could tell.
In fact I was so well protected from the cold that I felt ready to jump into an ice-cold flooded quarry if needs be. But I didn't.
It was a pity that the suit which had been specially tailored to fit me was such a close fit. I needed a lot of time to squeeze myself into it, and once the hood was pulled over, I felt I was clammed shut.
I suddenly realised why traditional divers carried that big brass-handled Siebe-Gorman knife. I thought that, had I need to get out of it in a hurry, the boys from the fire-brigade would have used something similar!
This is no criticism of the suit, simply an observation that personal tailoring is not without its problems. I asked the importer to send me a larger off-the-peg size in which to go diving.
The Red Sea in early June might be expected to be warm, and some of my fellow-divers had arrived with nothing more than dive-skins. It was 24¡C. I have never been too warm on a dive but I have often been too cold, especially as time passes.
In the Pinnacle Polar, I was as snug as a bug, and because the zip is positioned across the front, I needed no help getting in and out of it. I got a bit of grief from the boat captain for taking 75 minutes over a dive while the others were coming back well within the hour, but he was confusing me with someone who was not relishing the comfort of this suit.
I have to say that it proved to be one of the most comfortable and effective suits I have ever used: almost as warm as a drysuit but as unencumbering as a wetsuit.
The only downside was the extra lead I appeared to need to carry to counteract its natural buoyancy.
That said, I have decided to retain the suit a little longer for "extra testing". Just one other point for those who worry about such matters - wool is a renewable resource.
The Pinnacle Polar wetsuit is made by Neptune Aquasuits (New Zealand) and is distributed in Europe, including the UK, by Aquion. Available in a range of off-the-peg sizes, the suit costs £270.
Aquion 01404 890164, www.aquion-dive.com
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+ A semi-dry for the coldest conditions
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- Drysuit divers won't believe it
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KNIVES MAKE ME NERVOUS - as nervous as a solitary English football-supporter down an alley with a bunch of Galataseri yobs. I've made mistakes with knives in the past. The tip of my left thumb is now numb, because I've accidentally sliced it off so often.
What else makes me nervous? Well, before I started looking like a pillar of society, I often got stopped driving my car in the early hours by the boys in blue. What's in the bag, sir? Somehow I felt that a knife suitable for killing grizzly bears would take some explaining.
I am also quite nervous of ropes. My time as a boat-crew member taught me that ropes were important. They needed to hold when required and equally they needed to be let go as necessary. We always kept a large bread-saw next to both the forward and aft winches. There comes a time when a bend is under tension and the warp just has to be cut. As for ropes under waterÉ
Divers need a knife. Not for fending off sharks but for emergency use, in case you get entangled. It's a piece of safety equipment and, as with a fire-extinguisher, you hope you never have to use it but when you do, you expect it to work.
So what do I want from a knife? I don't want to cut myself unexpectedly. I want it to cut easily through a problem, not cause one. I want it to be a tool, not a weapon. I want it to be secreted away in my kit, forgotten until the day I need it.
The new Race Rescue Knife is aimed at the competitive sailing market. It has a 10cm blade of high-quality 425 stainless steel, so it shouldn't be reduced to a fragile rust stain in its sheath when you come to use it. It has a special protective yellow etching to protect it from such corrosion.
I found that its serrated edge made short work of almost any rope and its convex profile saved me from having to look out the Band-Aids. What it was not particularly good at was cutting through nylon monofilament line under water.
However, I experimented on a bit of nylon net and I am sure that a certain amount of extra energy applied would increase its efficacy. If you find yourself entangled, you'll suddenly discover that you do have that energy!
The Race Rescue Knife's handle is covered in rubbery plastic which gives a good grip, and it's bright yellow, so you should be able to find it easily. There's a shackle key in the blade that can be used for hauling out any nails that have their heads proud, but if you don't need that feature you could opt for a similarly priced version with a monofilament hook instead.
This knife would be useful for any dive-guide who has to swim down and tie a line round a wreck, the way they have been doing on the Thistlegorm for the past 12 years. It's a cat's cradle of lines down there at times, and the guides from heavier vessels have found that they need to use a wire hawser and shackle to be secure. I don't approve, but it's a fact.
One might find that an emergency arose and a line needed cutting fast, and the Race Rescue Knife is the tool for the job. It's better than a bread-saw, anyway!
The Race Rescue Knife and simple sheath costs £35.
Markat 01935 815424, www.markat.co.uk
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- Not so good for monofilament
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THIS IS NOT A PHOTOGRAPHY MAGAZINE. Although we use underwater photographs, until now we have always considered underwater photographers to be a minority of our readership and publish articles on the subject only from time to time.
All that is changing. Why? Because the digital age has put the ability to achieve good pictures while diving into the hands of everyone, rather than the few dedicated to the pursuit of nicely composed, well-exposed pictures. Digital cameras will record a picture almost every time, and you don't have to wait until after your dive to find out how successful you have been.
The SeaLife ReefMaster DC310 is a simple little black plastic 3.3 megapixel camera that comes with its own purpose-designed housing rated to 60m. There are two versions of the housing - one with a limited number of buttons, the other with all the controls accessible for those prepared to read the manual.
An external ancillary flashgun, essential for good colour-rendition at depth, and a close-up kit are also available. I tried the more advanced version, but without the external flashgun.
The main part of my test was to hand the unit over to an unsuspecting fellow-traveller who had no underwater camera of her own and see how she got on. In the event, Stephanie of Barefoot Traveller captured some very striking images, though most of them turned out to be blurred by camera-shake when I downloaded them later. Would-be photographers must realise that a digital camera takes time to record the image and this one seems to take quite a lot of time, so you must hold it still until the job is done.
The instruction manual comes on a CD - not very helpful in a boat, so familiarise yourself before rushing off on a dive with the camera. The CD includes a version of Acrobat Reader, which you need in order to see the instructions in PDF format. Of course you will not be able to follow those instructions to enable you to load Acrobat Reader until you have seen the manual. Catch 22.
All this is designed to help save the world's resources, so no printing out reams of paper to keep a permanent record, please. The only shame was that the contents index did not relate to the actual pages.
The DC310 has an 8Mb internal memory but you can slot in SD memory cards to increase its capacity as far as 256MB. This will give you (please wait until I find the right page in the 60-page PDF) between 96 and 2880 shots depending on the quality you choose beforehand. As I had only the internal memory and no memory card, I compromised JPEG compression quality to get nine shots at the best resolution.
The main control can choose set-up, viewing, video-clip or still picture mode. In set-up mode the wide choice of options includes white-balance, light sensitivity, LCD brightness, exposure compensation (auto and manual), and three choices of JPEG image quality and three choices of resolution. The higher the quality, the fewer pictures you can record. Most importantly, a "Sea" mode automatically selects the best combination of settings for underwater use. All easy to understand.
There are three focus settings, though it appears that you can use the camera only on one which equates to about 1m from the camera when it's in its housing.
There is an in-built flash that you can turn on and off at will, and this is used to trigger the optional external flashgun. Most often the in-built flash gave us the best results, but we were using it in very clear water.
The camera gives you three seconds to delete unwanted images as you go by pressing the shutter-release button a second time, or you can delete at leisure later.
The CD also has programs (MGI Photosuite and PhotoVista) for downloading and managing pictures on to a PC. There seemed to be none supported by Mac, but I used iPhoto and Photoshop and it seemed to work OK. However, the camera afterwards continued to tell me that its memory was full, even though according to the viewing mode there were no images left to delete, so I never got it to work again.
Looking at the pictures on the LCD at the time, things looked promising, but I was disappointed once I got the images home. I had assumed that this must be an entry-level underwater digital camera but its price is not exactly entry-level (see our recent comparison of underwater digital cameras under £500).
The SeaLife SL148 ReefMaster DC310 costs £400 with its housing.
Sangers 0844 4770121, www.sealife-cameras.com
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+ Range of useful accessories for underwater use
+ Straightforward to use
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- Instruction manual time-consuming to access
- More expensive than you would expect
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When Erik enters a room, the door-frame is filled and the sky darkens. He stayed at my house once, and I asked if he could do me a favour. "Is it a piano?" was his immediate reaction. In fact it was a stove I wanted to move, but Erik knew his role. Erik is Swedish. All the Swedes I know are big.
So I was disappointed to find that the Swedish-made Waterproof Antarctic 2000 drysuit sent for me to try in Men's Size Large proved a bit tight-fitting. I had to dispense with any idea of an undersuit. The things I do for you!
The special high-density 4mm neoprene promised to give me some insulation but it was winter, and I froze. It wasn't the fault of the suit, only the fit. At least I didn't get wet.
It's a neoprene suit, but very tough. The material has a nylon coating laminated to the outside. A polyurethane reinforcement to the part you sit on adds a non-slip characteristic.
Soft boots toughened with patches of Kevlar extend up the rear of the calf to make them easier to slip on. There are long vulcanised rubber knee patches.
There are no seams under arms or in the crotch area - places that would wrinkle and wear. The maker uses a technique whereby interior seams are protected by tape bonded smoothskin to smoothskin. A tiny amount of the nylon covering of the neoprene is shaved away to facilitate this. It's claimed that the result is as good as vulcanising the seams.
Latex wrist seals are concealed and protected under cuffs closed with a bronze zip. This also avoids heat loss to the water at a place where blood-flow is close to the surface of your skin.
Calling something "100% Waterproof" could be seen as optimistic, but the latex of the wrist seals is in a heavy-duty gauge and conical, so water didn't pass even my sinewy wrists. Heat-bridging at the wrists is avoided, as it is at the neck.
The heavy-duty latex neck seal keeps the water out all right, but latex is notorious for letting cold water chill the blood supplied to the brain. Waterproof has thought of that. A neoprene collar, redesigned since our drysuit comparison of 2003, covers this seal and is instantly adjustable by its all-the-way-round Velcro fastening. You can also overlap it with the neoprene skirt of the hood, so no icy trickles of water will spoil your day.
The heavy-duty cross-shoulder zip seemed longer than on other suits I have tried recently. It too is covered by a heavy slab of neoprene to keep the heat in. Two zipped thigh-pockets are described in the publicity material as "harmonica" style. I think they must mean "concertina".
Without an undersuit this drysuit was akin to a dry wetsuit in that no excess material slowed me down and I was able to slip easily through the water - perfect for dive-guides on Red Sea liveaboards at their coldest time of year.
As it is made of 4mm neoprene, you don't need as much undersuit insulation as with a trilaminate suit. But if you get a Waterproof Antarctic 2000, try it on over your Thinsulate first.
I expected the suit to come with Swedish-made Si-Tech valves but the example I used had the commonly used Apeks versions, a rotating inflation and shoulder-mounted auto-dump. They worked without drama.
The Waterproof Antarctic 2000 drysuit is not cheap at £708. It was waterproof - but will it be diver-proof? It looks tough enough. It comes in all-black or combinations of black and light grey or dark grey, and a range of off-the-peg sizes.
CPS Partnership 01424 442663
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+ Tough neoprene suit
+ No heat bridges at the latex seals
+ Waterproof
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- Off the peg sizes only
- Expensive
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A woolly wetsuit for British divers
