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Cold water diving...

It's vitally important that you use regulators designed for cold water

Try to avoid breathing off your 2nd stages when not in the water

Stay safe this winter!

  • Use regulators designed for cold water use.
  • Get air fills from reputable sources like Vobster.
  • Increase the amount of exposed metal by removing hose protectors.
  • Use lower pressure cylinders - ie. 232 rather than 300 bar.
  • Inflate BCDs or wings slowly to avoid over working the 1st stage.
  • Set the 2nd stage breathing resistance adjuster to minimum.
  • Abort the dive if your regulator free flows - even if you do stop it!
  • Overwork your regulator by airsharing or inflating a Surface Marker Buoy.
  • Breathe from or purge your regs on the surface.

Thankfully it never gets *that* cold at Vobster but you never know!

If a regulator free flows, ice can quickly form on the first stage!

Taking precautions can avoid all manner of winter freeze ups!

Keeping warm out of the water is as important as it is in the water!

For more info
on cold water diving...

Chill out in safety...

EU norm considers cold water diving to be when the temperature of the water is equal to or drops below 6 degrees C. Whilst the lake waters at Vobster Quay stay reasonably warm for most of the year, the water temperature can drop sharply during the winter months. Even during the summer months, deeper parts of the lake can still be relatively cold.

Regulators perform differently in cold water diving compared to temperate water - the aim is to do everything that you can to prevent the regulator freezing which, in turn, causes the dreaded free flow effect. By following simple guidelines, the risk of free flows can be minimised substantially.

Pressure variations in gases generate temperature variations - as most divers are aware, gases heat up during compression (filling a cylinder rapidly) and cool down during expansion (emptying a cylinder rapidly). This has an effect on the regulator 1st stage - the higher the pressure in the cylinder, the more effect it has. The cooling down effect of the 1st stage will be increased when the regulator is working on a 300-bar cylinder.

To mimimise the risk of free flows next time you dive in cold water, we offer the following advice...
  • To limit freezing risks, a lower pressure tank is recommended for cold water. The higher the pressure, the higher the risk!

  • Use regulators designed specifically for cold water diving! These regulators are often either environmentally sealed or use a special 'heat sink' that uses the cold water to 'warm' the 1st stage which limits the formation of ice. Look for regulators that meet the EN250 standard for cold water performance.

  • Avoid breathing from the 2nd stage out of the water when the air temperature is low. The aim is to minimise the cooling effect of the air and the diver's breath by not 'overworking' the 1st stage. Practising air sharing and deploying surface marker buoys in cold water is not ideal!

  • Get air fills from a reputable source - the drier the compressed air, the lower the freezing risk! Vobster's air is checked regularly for purity and is very dry!

  • A cool 1st stage can be warmed by the surrounding water - remember that the air will generally always be colder than the water, even during the winter months. Maximise the warming effect of the water.

  • The greater the amount of exposed metal, the greater the warming effect of the water can be maximised - pull back hose protectors on metal hose ends. This also helps to extend the life of your hoses as it stops debris and water trapped against metal fittings from causing corrosion.

  • Inflate BCDs and wings slowly - preferably during the exhalation phase to 'unload' the 1st stage.

  • If you have a 2nd stage with a breathing resistance adjustment, remember to always have the adjuster set to minimum when it is not being breathed from.

  • For further advice on cold water diving specific to the equipment you use, consult with a qualified service technician or the equipment manufacturer.
It's important to understand why free flows occur and how to handle them should they ever occur. Regulator 2nd stages essentially act as pressure relief valves - they are designed to do this. Normally in temperate diving, if an adjustable 2nd stage purge button hits the water or is even lightly touched when it is set to maximum but not being breathed from, it can go into free flow.

To stop this sort of free flow, put a thumb or finger over the 2nd stage mouthpiece to break the flow of air and then - if the 2nd stage offers such a facility - set the breathing resistance level to minimum. If this doesn't stop the freeflow, get your buddy to close and reopen the valve.

Regulators - when set up correctly as per manufacturer's procedures - are design to easily give the diver air to breathe. A 1st stage freeze will cause the mechanism to free open within the 1st stage which will cause a 2nd stage free flow (remember it's a pressure relief valve!). Follow your training and ABORT THE DIVE.

If the cause of the freeflow is thought to be a 1st stage problem, the regulator will still not work properly even on dry land and in a warm environment. Also, try to identify where the free flow came from - was it a 2nd stage or your Autoair or BCD/wing inflator?

Keeping yourself warm 'n' cosy with this winter!

Equally important as ensuring that your dive kit is up to the rigors of the British winter, you need to keep yourself warm and cosy when the temperature starts to drop. Below you'll find some common sense advice on surviving the worst that the winter can throw at you...
  • Thermal Protection - Whilst a semi-dry wetsuit might suffice during the summer, we recommend a drysuit during the winter months. If you must dive in a semi-dry, keep your dives short and shallow - we recommend a dive no longer than 20-30 minutes. Any longer than this and you could risk hypothermia. Know your thermal limits and stick to them.

    It's worth putting some real thought into the sort of undersuit you wear under your drysuit too. We'd recommend a good 200 or 400 gram Thinsulate or a Weezle Extreme with a Fourth Element Xerotherm base layer. Trust us - undersuits don't come much warmer!

  • Hood & Gloves - It might seem obvious, but you'd be surprised by the amount of divers that turn up without these two vital items of equipment! During the winter months, we'd recommend a good 7mm fleece-lined hood and some 5mm neoprene gloves. For extra toastiness, a decent pair of dry gloves are a good investment.

  • Hot Food & Drink - To keep the winter chills at bay, tuck into a hearty breakfast containing lots of heat-generating carbohydrates to give your body fuel to burn throughout the day. After each dive, warm yourself up with a hot drink or soup and something hot and filling from our catering van.

  • Pre- & Post-dive - Stay warm before the dive. Heat loss is gradual and can start long before you get in the water. Try to stay warm between repetitive dives - standing around in wet gear between dives can add to your body's loss of warmth through evaporative heat loss. Instead, get warmed up as soon as possible after a dive. Towel yourself dry, get into some dry clothes and then enjoy a hot drink!

  • Hot Shower, Anyone? - Although it may seem very tempting, jumping straight into a hot shower after a cold dive is not a good idea. The rapid increase in temperature can stimulate bubble formation, increasing your chances of a skin bend. Instead, towel off, change into dry clothes and get a hot drink down your neck!

Dry gloves are a good buy when the temperature drops!

Take away the chill with a hot drink and a bacon buttie!

Do yourself a favour - dive in a warm dry suit this winter!

Don't be tempted to jump straight under a hot shower!

22-05-2019    07:30

It’s a tranquil morning. #goodmorning #vobsterquay #supsomerset #sup

POSTED: 18th June 2019


Check this out, the grand switch on has happened. You can now see whether you have time for the last lap without fearing the wrath of the air horn. Fully lit with LED lights, even in the dark there's no excuse! Visible from the centre of the lake - just... [more]

POSTED: 14th June 2019

Suunto Demo weekend Sat 22nd and Sun 23rd June at Vobster Quay. Please do come and visit the guys.

POSTED: 13th June 2019


Many thanks to Peter Wilson of Miflexhoses and KUBI Dry Glove Systems for sponsoring us this fabulous new clock for the Quayside. No excuses for late exit now, as it comes fully lit ready for night dives and swims. #latenightswimming #nightdives #kubidrygloves #miflexhoses

POSTED: 12th June 2019

EVERYTHING WE DO - we do for you

The 2019 shelter is progressing nicely, almost ready for the summer with Suunto Diving. #summerishere #suuntodiving #vobsterquay #wildswimming #openwaterswimming #greatviz

POSTED: 07th June 2019

Solstice Swim - Friday June 21st at 4.55am

Please join us to celebrate the Solstice this year by partaking in the early morning swim. We will have a lifeguard on duty from 5am-8am, and breakfast will be available afterwards.

Thanks to Sally and Geoff Hooper for these fab photos from last year, and looking forward to this years... [more]

POSTED: 07th June 2019

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