It was on June 23 that 12 Thai boys and their football coach, on a school trip, entered the Tham Luang cave in the northernmost province of Chiang Rai and failed to emerge.

They have now been trapped for two weeks - and it was 10 long days before British divers were able to navigate the narrow, flooded passages to reach them in a race against time with the monsoon rains.

Yet, the concept of time in such dank subterranean darkness becomes rather difficult to fathom. What day was it, the boys inquired of the divers when they arrived, unaware of how long they had been waiting for their would-be rescuers.

Now, as time ticks on, they continue to sit tight, as everyone from the Thai authorities to the British diving team and US billionaire Elon Musk, tries to establish the safest way to free them from their prison.

That sense of disorientation is something Helena Overton remembers well. Almost 11 years ago, she too was trapped in a Thai cave, when a travel adventure went fatally wrong.