Coping with the cold
The sea around Antarctica remains cold year round with temperatures reaching lows of nearly -2 and rarely reaching above 0 degC. Because of this we have to take extra precautions when diving to make sure that we stay warm.
The first precaution if that we wear drysuits - neoprene suits which are sealed at the neck and wrist so that your body stays dry. This means that we can wear lots of thermals underneath to ensure we don't get too chilled underwater and we can also add more air to our suit underwater for insulation.
We also use full facemasks which mean that our faces stay a lot warmer too. This is all very effective and so far, even on hour long dives, it has only really been my hands and feet that really feel the cold
Of course all of this extra clothing and air in our suits means that we have to wear a lot of weight in order to sink. My muscles are certainly getting a work-out here in Antarctica!
(Click images to see them full size)
We have a few boats here in Antarctica but the ones we most commonly use are Erebus and Terra Nova (named after two famous ships from the era of early Antarctic discovery - Terra Nova was Scott's ship for his last expedition). They are all looked after by our dedicated boatman, Tim and we have a number of people on board who can skipper them.
My first big surprise with the boats is that they are lifted in and out of the water by crane before and after each dive! This is to prevent ice damage and allow for easier maintenance but also makes loading and unloading the dive equipment much easier.
A British Antarctic Survey Boat being lowered into the water from the wharf
When out on the water the main challenge for our skippers is navigating through the ice and icebergs. A piece of ice which can look deceptively small from the surface can deliver a hefty wallop to a boat travelling at speed.
Erebus and Terra Nova off Rothera Point
Another difference between diving in the UK and Antarctica is the presence of large predators which can pose a risk to divers. The two which we have to be careful of are Orcas (killer whales) and Leopard seals and if any are seen around Rothera then we aren't able to dive for a while.
Before every dive we spend half an hour on "sealwatch" making sure that it is safe to get in the water. In addition we also have full communications at all times with the surface and our diving buddy. This is really useful for discussing science underwater but also means that we can immediately be alerted if a potentially dangerous animal is in the vicinity.
Ice and icebergs
Ice and icebergs can also pose a challenge to divers, even in the Antarctic summer. Large icebergs can move quite fast if the wind is blowing and will often gouge the seabed as they pass - a diver wouldn't want to get in the path of that! They can also become unstable when they start melting and large pieces may break off or they might even tip over altogether.
Because of this we take extra care to stay distant from icebergs both above and below the water. Ice is a bit more tricky to avoid so we always have to make sure we look up when we are returning to an icy surface so we don't bang our heads!
A diver ascending in ice
© Ash Cordingley
Despite the challenges Antarctica is a fantastic and fun place to dive and is full of life - I'm looking forward to sharing some pictures of the weird and wonderful creatures we find here in my next blog post.
Scientific diver, Kathy Dunlop and a ctenophore
© Ash Cordingley
Jen's research is being undertaken as a collaboration between:
Heriot Watt University, Natural History Museum, UMBS, Millport, and the British Antarctic Survey.