"There was only one word for it - biblical".

Noah Bickler is recalling his gap year in Israel, a time learning Hebrew, studying Zionism and the nuances of the Israeli-Palestinian conflict combined with eye-opening trips around the country.

He has particularly fond memories of trekking in the Negev. "Every night, it was just us and the desert," he remembered. "It was breathtaking."

Now back home in Leeds, and about to start a degree in law and politics at Manchester University, Noah, who went to Israel with the Habonim Dror youth movement, still hankers for the Holy Land.

"I really miss my gap year," he said wistfully. "It was a life-forming experience."

For Jewish school-leavers, the gap year in Israel - or shnat as it is known after the Hebrew abbreviation for "year of service" - is a long-established tradition. But its popularity has see-sawed in recent times.

Up to four years ago, upwards of 150 school-leavers would make the annual trip. But numbers dipped sharply in 2011 when only 54 people signed up.

By 2014, the figure had recovered to 130, and this year 98 students have registered, according to UJIA, the umbrella organisation overseeing gap-year programmes.

The reason for the sharp fall in numbers in 2011 was financial. That year university tuition fees increased from £3,375 to £9,000. This and the recession at the time meant families were no longer able to fund their children's foreign excursions.

In addition, students, burdened with the weight of hiked-up loan repayments, could no longer justify to themselves a year abroad. More pressing was the race to graduate and secure a well-paying job as quickly as possible.

"It is a bit of a paradox that people are so worried about getting into the job market, but could increase their chances of employment if they took a gap year," said Roy Graham, director of programme and planning at UJIA, which co-ordinates Jewish youth movements' year-long Israel trips and partners with the Israeli agency Masa UK, as well as yeshivahs and seminaries.

"Students are under huge pressure, and the worry over being left behind their peers is playing heavily on their minds. The graduates of our programmes are more confident, more able and more likely to take on responsibilities in leadership. Because of the experiences they have had, they are just on another level."

When numbers first dropped, UJIA started to provide bursaries to families who could otherwise not afford to send their children on gap years. In 2014, the charity provided assistance totalling £75,000.

Mr Graham said: "It is an absolute priority for us to look at the declining numbers.

"There has been a little bit of recovery, and we are looking at what is possible to increase numbers further."

Even with a bursary, expenses can be eyewatering. Prices start at £6,000, while an average nine-month programme can stretch to £11,000. But Mr Graham insists the gap-year experience is a worthwhile investment.

"It's not just about strengthening the students' attachment to Israel, it's also about taking it to a higher level," he said. "It allows people to engage with the full complexity of Israel in a very sophisticated and deep way.

"The gap-year students are learning Ivrit, are volunteering and are working with Israelis. They get a level of understanding and appreciation of Israeli society that you cannot get outside of such an immersive experience.

"The Institute for Jewish Policy Research found that a long-term Israeli programme was the most effect intervention for aiding a person's Jewish identity."

Most of those who go to Israel have long been involved with Jewish youth movements, meaning they have probably already spent considerable time either socialising in Jewish environments or travelling to Israel.

"Israel provides comfort and familiarity," said Joel Macadar, Masa UK's recruitment co-ordinator.

The organisation works with UJIA, as well as students who are unaffiliated to youth movements, offering gap year and postgraduate options including internships at Israeli companies, volunteering opportunites in Jewish and Arab schools and farming jobs on kibbutzim.

"Obviously, most of these people have been to Israel before, which has an effect on their decisions," Mr Macadar said. "We have a lot of anxious parents calling us, who find relief in the notion that their children will find their feet in Israel. It is an option they feel comfortable with."

For Annie Levy, 19, from north London, Israel was the only gap-year destination she was interested in. She returned to the UK in June after eight months in the Holy Land with RSY-Netzer, the movement she has belonged to since the age of 14. Highlights of the trip included working on a kibbutz and attending a seminar on the West Bank.

"I wanted a greater understanding of Israel and all the questions surrounding Zionism," the former-JFS pupil explained. "I also wanted to establish my own personal values. My Jewish identity has really developed. I have more confidence now to debate and put forward my opinion, and to not be afraid to ask questions."

The 19-year-old feels the experience will be invaluable when she leaves for Leeds University to study international history and politics next month.

"I have developed a lot of people skills," she said. "I can also see with hindsight how important it is to have a break. Being in the education system from the age of three to 21 is quite ridiculous. It really gave me perspective being out of the system for a year."

Her friend, Tatiana Hill, agrees. A six-month stint in Israel with Noam, the Masorti youth movement, helped her decide on a career path. The 19-year-old, who attended King Alfred School in Golders Green, has decided to return to Israel to do a year of military training, and then hopes to join the British army.

"Taking a gap year showed me that there are different paths to follow and that I can fend for myself," she says. "Even when things seemed tough, our motto was: 'we can do this'.

"I remember arriving on the kibbutz, which is a million miles away from London. We all sat there thinking: 'what is this?' But we settled in and I loved it. I can definitely say that I am more mature now than I was when I left home. But then, I am sure it would have that effect on anybody."