Princess Kate admitted her husband thinks she is ‘crazy’ when it comes to her unusual hobby. (Image: PA)

Princess Kate has a passion for an extreme sport that even Prince William finds “crazy”, it has emerged. The Princess of Wales’s penchant for cold water swimming, including in the dark, was revealed during her chat on Mike Tindall’s podcast, The Good, The Bad and The Rugby.

During the conversation with Mike Tindall, who has been married to Zara Tindall since 2011, Kate Middleton divulged her lifelong commitment to physical activity.

She said: “I can always remember being physical, using our bodies, whether it’s walking, climbing the lake district, in Scotland [or] swimming from a young age. [My parents] always encouraged us to be physically active and sporty and they always encouraged us into doing team sports and trying things.”

Kate then confessed her enthusiasm for the chilly pursuit, which is known for its health benefits and involves braving unheated pools or outdoor locations for swims in winter conditions, sometimes even at night. She expressed her zeal: “Cold swimming – the colder, the better. I absolutely love it. Slightly to the point where William’s [saying] ‘You’re crazy’ and it’s dark and it’s raining. I will go and seek out cold water. I love it.”

It’s clear that Princess Kate’s adventurous spirit extends to the water; back in 2015, it was disclosed that she is also an accomplished scuba diver.

Kensington Palace has confirmed that the Princess of Wales has achieved a Professional Association of Diving Instructors (PADI) Advanced Open Water Diver qualification, enabling her to explore ocean depths of up to 98 feet (30 metres).

Prince William thinks Kate is ‘crazy, for pursuing a unique hobby. (Image: Getty)This prestigious diving certification allows her to join Prince William, an experienced diver himself and president of the British Sub-Aqua Club, on underwater adventures. A spokesperson for Kate told the Telegraph, “Diving is something the Duchess very much enjoys, and the Duke of Cambridge, who is of course president of the BSAC, has said in the past that he is hopeful his children will become interested in the sport.”

To earn this accolade, the royal completed five distinct dives, including a deep dive and an underwater navigation challenge. The course equipped her with skills to manage the physiological impacts of deep scuba diving and proficiency in using essential gear such as a compass and dive knife, crucial for emergencies like entanglement in fishing nets.

In that same year, Prince William shared his enthusiasm for the sport, expressing his desire for Prince George, then two years old, to take up diving as well.

“Scuba diving really has opened my eyes not only to many extraordinary sights but also to the responsibilities that we have as guardians of the underwater world,” William expressed. ”I hope that one day my son, George, will also experience the wonders that snorkelling and scuba diving have to offer.”

“At the moment bath time is quite painful,” he quipped. “But hopefully donning a snorkel and mask might calm him down.”