The Duke of Cambridge was put to work under water planting coral – by one of his Earthshot Prize winners.

William donned a wetsuit and dived into the sea during the final engagement of this eight-day Caribbean tour with Kate.

They capped off their troubled Queen’s Platinum Jubilee trip by dropping in on old friends Sam Teicher and Gator Halpern, at Coral Vita, on Grand Bahama.

Kate, 40, matched the colour of the coral farmed and protected by the entrepreneurs by wearing a coral pink dress.

The duke had spoken to the winners of the Revive Our Oceans category in his £50 million Earthshot Prize, designed to “repair the planet”, on a video call after the star studded prizeshow last September.

But this was the first time the duke has visited one of the five 2021 category winners.

As he arrived, he said: “Here they are. Look who it is, the famous double act.”

The award winning entrepreneurs showed William and Kate a mark on the wall how high the water reached during Hurricane Dorian in 2019.

William said: “That’s incredible.”

Spotting the Earthshot Prize mounted on the wall, William waved his hands in delight and said: “You’ve done a good job with it.”

Mr Teicher and Mr Halpern took the duke to see several of the 28 water tanks where they are growing damaged coral.

It can take a year to grow a so-called micro piece until it is large enough to be replanted on the sea bed.

They also showed how to brush off the algae to keep the coral healthy.

Coral Vita also heat the tanks to the correct temperature to add resilience to the coral so when it is transplanted into the sea, it can adapt easily to warming oceans caused by climate change.

Staggered William said about coral: “Are you saying because climate change is so fast it is not having enough to time to adapt? You are making it happen in a faster time frame.”

Mr Teicher added: “We stress-harden the coral.”

The duchess then gave a helping hand at Coral Vita’s Mangrove Nursery.

She potted and watered a mangrove then shook muddy hands with some of the volunteers.

She laughed adding: “Don’t worry I’m used to it. I’ve got three kids.”

The duke then climbed aboard a boat and was taken out into the sea to plant some coral.

The event was private without media present, but William was joined by his personal photographer. His inclusion on the trip was privately funded and he travelled with the Cambridges throughout the tour.

Photographs and video of William underwater will be released in the autumn, it is understood.

William’s yacht was led into the sea by a Bahamas police boat carrying 10 people including a medic and eight uniformed officers.