Both free divers and scuba divers take on the five miles long, 56 metres deep Coniston Water in awful conditions with presenter Helen Skelton donning three coats.
This is in aid of newly qualified doctor Tabitha who travelled to the Lake District the day after her graduation to try out her friend’s new paddleboard when things took a turn for the worst.
Newly qualified doctor Tabitha (Image: BBC) She said: “So we were laughing and filming each other, it was quite funny, and then it got a bit windy and I just lost my balance and fell in.
“I fell into the water and came back up and I thought ‘something’s missing’, like, what’s fallen off me’, and I realised that my phone had come away from my neck – it was just then pure panic mode.”
After six years of studying long and hard to become a hospital doctor, Tabitha lost all the pictures of her graduation which included those of her mum, dad and grandparents.
She added: “Because I had such a journey to get through university, to get to the end and graduate was such a big moment for me and for my family.
“It was such a nice day and it was overshadowed by the fact that I didn’t have anything to show for it almost.”
By studying a video of when Tabitha fell in, the team set out in horrendous rainy conditions to try and find her lost phone.
The metal detecting team at Tarn Hows (Image: BBC) Meanwhile, in the idyllic Tarn Hows, metal detectorists have been given a long list of items that have been lost at one of the most popular walking spots in the Lake District.
Among the Queen Victoria and Queen Elizabeth I coins discovered, team member Shirley finds two very unusual rings in separate locations that are believed to be linked.
Social media detective Mui sets about trying to track them down back at the boat shed.
One of the usual rings found on the path around Tarn Hows (Image: BBC) Crafter Jen, who has re-purposed bag company Dirtbags based in Kendal, also features in the episode and is challenged to give an entirely new lease of life to discarded tents and camping chairs.
To find out the outcome of the team’s adventures, visit BBC iPlayer Series 1 episode 3.