I qualified as a PADI Open Water diver in Thailand in 1999. On returning to my home in North Wales, and wanting to take my diving further, I signed up for an Advanced diver course, training in Vivian Quarry, a small secluded quarry lake in Llanberis.

It was an ideal site to train in. I felt safe in the still, enclosed water. I should have thought twice about starting the course in December though! I often wondered why I was getting into a lake when it was snowing!

I soon got the hang of diving in a drysuit - a watertight suit which can be filled with air to keep you warm. I was very cosy but it didn't stop my face from going numb with the cold after ten minutes! But it was worth it as my instructor and I often had the whole lake to ourselves to explore the eerie quarry ruins.

It was here I did my first night dive. Swimming out into the lake under moonlight and a starlit sky in perfect silence is quite an experience.

Last October I had the opportunity to dive in the busy world of the Great Barrier Reef. As I have an interest in marine biology, this was the place for me. The colours and shapes of the countless forms of life underwater provide constant entertainment. Parrotfish in all sizes were everywhere, constantly crunching the coral noisily in search of food.

Occasionally a turtle would slowly flap past, and if we looked hard enough we got glimpses of small whitetip reef sharks cruising the outer limits of the reef.

Maori Wrasse, huge colourful curious fish, have become habituated to divers on many of the dive sites, so when I realised I was being followed by one of about 3 ft long, I couldnt resist a stroke. I was delighted when it didn't move away, it seemed to enjoy the opportunity to get a good look at us divers!

I wanted to do another night dive, so I joined the pre-dive briefing to be told what to expect to see with my torchlight under the water. Red eyes reflecting back were good I was told; these belonged to shrimp. Green eyes were to be avoided sharks eyes!

By the end of my dive I hadn't seen any sharks. But when I shone my torch around for one last look and spotted an unmistakeable pair of green eyes cruising past. They belonged to a shark of around six feet long. I was pleased until I continued shining my torch and saw another shark, then another one...

There were at least five of them circling us, keeping a constant eye on us. It wasn't long before we lost our nerve and climbed hastily out of the water. I think they were Bronze whaler sharks considered potentially dangerous. I was pretty pleased with myself!!

Now I'm back in North Wales and hoping to continue diving in local waters. It might give me a numb face, but at least the wildlife is a little safer!