The Duke of Cambridge has joined a fast patrol boat through the Strait of Hormuz.
As part of his four-day tour of the Middle East, Prince William took to the water with the Royal Navy of Oman, learning about the naval strategies in place to protect British-flagged ships from Iranian attack.
British shipping has been targeted by Iran since tensions peaked in the summer, which saw the Islamic Revolutionary Guard seize a British-flagged tanker.
Visiting Oman's Ras Musandam Naval Base, the Duke learned how the notorious waters are monitored, before slipping on a lifejacket and taking to the high seas.
More than 40% of the world's crude oil cargo passes through the channel.
US President Donald Trump’s withdrawal from a nuclear deal with Iran last year sparked a number of events in the Persian Gulf this summer.
In September, Tehran released the British-flagged tanker more than two months after the seizure – crew onboard the Stena Impero accused of violating international maritime law.
It is thought the move was in retaliation to a Royal Marine operation two weeks prior, detaining an Iranian tanker holding more than £100 million worth of crude oil on suspicion it may have broken EU sanctions with Syria.
Now, 90 members of UK Army, Navy and Air Force troops are working with Omani forces in the Middle Eastern region, to prevent a repeat of events this summer.
Three patrol ships now monitor 100 cargo ships per day in the area.
Captain Richard Moss is in charge of the British contingent.
"Oman has a big role in the maritime security of the lawful trade conducted through the Strait of Hormuz," he said, adding that personnel will support training and surveillance capabilities.
The visit to Oman marks the closing stages of the Duke’s tour, a senior palace source saying: "The Duke of Cambridge's visit is of huge importance, standing shoulder to shoulder with the troops dedicating themselves and their work in the region."
The Prince is on a four-day tour of the Middle East, having observed urban warfare training in Kuwait on Tuesday.