The Prince of Wales enjoyed the “best day of my life” when he was encouraged to spray pond water at the press – all in the name of science.

William aimed a syringe full of the cloudy water at photographers and journalists when he joined school children collecting DNA samples for NatureMetrics, a finalist in his environmental Earthshot Prize awards project.

The future King visited the Guildford-based company to learn more about its work analysing environmental data to provide clients with a comprehensive map of life in a forest, lake or even the air, and quipped “does this mean you can find the Loch Ness monster?”

The Prince of Wales with local school children as they prepare to filter DNA samples through a syringe (Richard Pohle/The Times/PA)

Dr Kat Bruce, founder of NatureMetrics, suggested the prince and the youngsters aim at the media as a joke and William eagerly joined in, and said “great idea”.

The group pushed the plungers on the syringes, topped with a filter to collect the environmental DNA, but the sprays of water fell short and the prince quipped “Oh nearly, so nearly” adding: “This is the best day of my life – great fun.”

Two further attempts failed and the prince left the chilly outdoors to be given a tour of NatureMetrics’ nearby labs, where he donned a white coat and gloves to help in the first steps of extracting DNA from a sample.

The Prince of Wales makes a mini extraction of DNA during a visit to the lab of 2024 Earthshot Prize finalist NatureMetrics in Guildford (Richard Pohle/The Times/PA)

He was shown the rest of the process including a DNA extraction machine that produces the DNA code sequence that allows the team to identify everything from bacteria to a blue whale.

William told NatureMetrics’ chief executive officer Dimple Patel: “So much of what the environmental world needs right now is data. This is fantastic you guys have got this ability to be able to tell us what’s really there.

“There’s a lot of guesswork, there’s a lot of painstaking volunteers and science going into this, but actually what we need is to be able to understand bigger, large-scale projects as to what is in each area.”