WATCH: Queen visits Royal Navy frigate to celebrate its 20th anniversary

The Queen has heard first-hand about the Royal Navy's relief effort in the aftermath of Caribbean Hurricane Irma - and could not resist trying out a piece of a fireman's safety equipment.

The crew of a Wildcat helicopter described the devastation they saw when deployed to the West Indies when the Queen visited the warship HMS Sutherland, to celebrate the 20th anniversary of the vessel's commissioning.

Moored in London's West India Docks and surrounded by the skyscrapers of City banks, the Type 23 frigate looked an incongruous sight.

Its commanding officer, Commander Andrew Canale, is well known to the Queen as he served for a number of years as her equerry.

On the vessel's deck, the Queen chatted to the flight crew of a Wildcat helicopter who described their humanitarian experiences while deployed to the Caribbean, separately from HMS Sutherland, as part of Operation Ruman.

Later, when the Queen came across four of the frigate's firefighters, she could not resist pressing the fire horn of Engineering Technician Stanley Money, 21.

Chief Petty Officer Peter Manning, 38, who is in charge of the fire crew, laughed with theroyal visitor as she prodded the horn, which is worn on the shoulder and looks like an old-fashioned bicycle horn, and then gave it a squeeze.

He said later: "The Queen asked what it was for and I told her they sound it in distress. If they get into a distress situation during firefighting - it could be dark with smoke - it lets others know they need help."