Appeared in DIVER August 2007

John John Bantin has been a full-time professional diving writer and underwater photographer since 1990. He makes around 300 dives each year testing diving equipment.


REMEMBER THE WOOLLY BEAR You wore this marvel of 20th-century diving science under your drysuit to insulate yourself from the cold water beyond. It was made of an open-weave material, so that air injected into the drysuit had no chance of becoming trapped when the time came to ascend.
Marvellous! Or at least it was, until you climbed out of your drysuit and found that a chilling sea breeze blew straight through it.
Since then, weve had Thinsulates and micro-fibres. It seemed that modern hi-tech materials had seen off traditional organic fabrics permanently until the renaissance of Merino wool, a material so prized in medieval times that exporting a Merino sheep from Spain risked incurring punishment in the form of a particularly excruciating death.
Well, someone got away with it, because a sub-species of that breed, and a highly prized one, is farmed in the mountainous Lord of the Rings region of South Island, New Zealand.
We have tested Pinnacle wetsuits that make use of Merino wool in the past. The companys diving suits originate from New Zealand, although they are made in China.
The hardy New Zealanders know about surviving in cold seas. They also know that the fabulous insulating qualities of Merino wool actually improve if the fibres get wet, as they saturate and swell up to provide even more insulation.
I often use unfamiliar drysuits, so make sure to carry a spare set of underwear when I go drysuit diving. I welcome the chance to wear an undersuit that improves as it gets damp, as drysuit valves so often seem to let water in.
It may seem convenient and modest while kitting up in a public place to put your
undersuit on over your underwear, but its a decision often regretted on a long drive home. Hence the spares.

The Pinnacle Merino Evolution is made in layers. Theres a Merino wool inner layer, with a nylon outer covering to keep the wind out. Between them are a 100g/m2 layer of Thinsulate and a 250g/m2 layer of technical fleece.
Its quite slim-looking, without that duvet look of some popular undersuits. Its neoprene cuffs and ankle seals are there, I suspect, to prevent air getting into the suit, so the only insulating air you take with you is that provided by the woollen fibres.
That said, the shoulders and wrists have ventilated netting sections. Where air injected to keep the volume of the drysuit constant might get trapped within the nylon outer covering, these sections allow it to escape.
The top pocket is zipped for safe carriage of items such as car keys, cash and credit cards.
The undersuit is quite heavy. For example, one to fit me weighs 2.4kg, some half a kilo more than the equivalent Swiss micro-fibre undersuit.

Were talking clothes here. Some people see the soft caress of a Merino wool lining as second only to that of South American vicuña or Indian Kashmir wool, while others regard it as being as punishing as a hair vest.
Comfort is a personal thing. The mental scar caused by having to wear knitted woollen swimming trunks during an experimental (on my mothers part) phase of my childhood, has long faded (wool swells up and stretches when it gets wet). Nowadays, I like wool.
Theres a soft knitted collar and a neoprene gusset for flexibility at the groin. The diagonal entry side pockets are trimmed with a soft towelling-like material, and theres a normal two-way zip that allows a gentleman a degree of convenience when Nature calls.

Who knows how well this undersuit keeps you warm Its a very subjective thing.
I would guess that the Pinnacle Evolution is as warm as any other Thinsulate style suit in a 100gm version, but that the Merino wool lining offers a bit of luxury.
It may not be as warm as one of those micro-fibre suits that fluff up to fill every available space within your drysuit. However, that assumes that your drysuit is a little more loose-fitting than is strictly sensible.
It also assumes that you produce a lot more heat internally through the energy released
by propelling yourself through the water in such a suit.
The Pinnacle Merino Evolution works as well with a neoprene drysuit as with a slim-fitting membrane suit. Neoprene seals inevitably leave me feeling a bit damp, but the Merino wool then comes into its own. Well say no more about leaky drysuit valves.


PRICE £170
SIZES 8 sizes XS to XXXL
CONTACT Oceanic SW,, 01404 891819
DIVER GUIDE width=100% width=100% width=100% width=100% width=100% width=100% width=100% width=100% width=100% width=100%