Huddled in a huge flying jacket to stave off the cold, Jacqueline Wolsey nervously tucked into a Fry's chocolate cream bar as the aircraft she was training in slowly circled the ground.

Stashing the chocolate bars in her pocket for sustenance, she ate with increasing anxiety as the weather turned on her and the pilot.

Engulfed by thick mist, the Anson and Swordfish aircraft was slowly running out of fuel as the pilot desperately tried to find the runway.

"I'll never forget the weather closing in on us one day as we were returning to base," Jacqueline says.

"The Canadian pilot flying with me that day becoming increasingly concerned that we were lost and running out of fuel as he circled looking for land for what felt like an eternity, banking round and round in the mist."

Required to fly with pilots to aid her Women's Royal Navy Service (WRNS) training, trying to better understand how the aircraft were operated and to help with accurate weather reporting, Jacqueline's stomach turned as the aircraft continued in a loop.

"I was soon feeling very sick indeed - with anxiety and rising nausea."

Luckily the pilot landed the aircraft safely, but Jacqueline's abiding memory is not one of fear but a dislike for fondant-filled sweets.

"I haven't been able to touch another Fry's chocolate bar since."

Aged just 17, Jacqueline signed up to the WRNS in 1943 as a Wireless Telegraphist operator, specialising in VHF/DF communications and trained to listen for British aircraft off the coast of Scotland.

In the midst of a terrifying war, she would sit on coastal watch in freezing wooden sheds in the dunes, listening for pilots radio transmissions, reporting and recording their positions. But she would also hear, with alarming clarity, the German U-boat signals and transmissions too.

After training at RN Air Stations Arbroath (HMS Condor) and Stretton (HMS Blackcap), she served until the end of the war in a role similar to a modern air traffic controller before reluctantly leaving in 1946.

Servicemen were returning home to take up the roles she had excelled at and says she felt pressured to start a family.

Now 90-years-old, Jacqueline looks back on her time as a Wren, recalling the experience as "such a terrible responsibility for such a young woman."

Founded in November 1917 in the midst of the First World War, the Women's Royal Naval Service (WRNS) was one of the first of three services to officially recruit women in the midst of war, encouraged to sign up to allow men to fight.

While it was temporarily disbanded after the war ended, the threat of Hitler saw the service reinstated in 1939 and made a permanent part of the Royal Navy when the war ended in 1945.

Nicknamed Wrens after the service's acronym, women would take on tasks the Royal Navy had once thought to have been beyond their capabilities. Wrens were operating radar and communications equipment and providing weather forecasts, operating harbour launches and tugs close to the shore and some trained as pilots.

Those with language skills were drafted to stations around the coast to interpret and translate signals from the enemy and many Wrens were involved in naval operations including the D-Day landings in June 1944.

Ahead of the service's centenary next year, women who have risked their lives for their country have spoken of their experiences to celebrate their Women's Royal Naval Service heritage.

Seven decades after Jacqueline sat in freezing cold temperatures listening out for faint pulses from morse code transmitters, Lt Helen Edwards has spent almost ten years supporting air operations at sea during her 25-year Naval career.

She too began as a Wren at HMS Raleigh, just as new roles began to open up to women in the Senior Service - women did not serve in Royal Navy ships until the 1990s.

Helen says: "I joined because I was looking for an adventure, a job in which I wouldn't have to commute to an office job, one in which I would get to meet new people, try new activities and one that would be challenging."

While Jacqueline's life as a Wren was pioneering, paving the way for women to apply for military roles, Helen's has continued to trailblaze in a modern era.

Initially qualifying in the Radar Branch, she was soon amongst the first batch of women going to sea in a mixed ship's company in frigate HMS Beaver before specialising in aircraft and subsequently air traffic control.

She became the first female warrant officer in the aircraft control branch and was deployed to Afghanistan in 2011, working alongside NATO partners at the US Marine Corps' Camp Leatherneck in Helmand Province, processing and prioritising bids for support helicopters in the flying programme.

Coming ashore this summer, Helen joined the operations room of the London Area Control Centre at RAF Unit Swanwick, the military element within the National Air Traffic Services (NATS) operation.

As part of the Navy's Warfare branch, she is responsible for controlling airspace around ships and task groups at sea, ensuring the safe integration of military aircraft through the civilian airway structure.

Now she is training as a military area controller at Swanwick, covering airspace from Newcastle to East Anglia,

She explains: "It's a large piece of busy airspace, where military jets of both the RAF and USAF operate daily.

"There is less controlled airspace over this side of the country, so it is also our job to safely control the civilian planes through."

With a career which has spanned the space between becoming a Wren and taking command of a field which was once dominated by men, Helen is looking forward to celebrating the role of women in the Royal Navy next year.

She says: "I have had a thoroughly rewarding career, met some amazing people and have experienced so many incredible opportunities."

While Jacqueline adds that she cannot wait to celebrate her time as a Wren as the centenary rolls around next year.

The WRNS100 Centenary celebrations will launch on International Women's Day on March 8 next year, highlighting the impact women have made on the Royal Navy since the Wrens first enlisted 100 years ago.