Sheffield Sea Cadets showcased their undercover skills to throw a birthday surprise with a difference as they celebrated 80 years of history.
Dignitaries who gathered for a special anniversary parade were given a shock by the youngsters, who demonstrated their field craft by donning camouflage and sneaking up behind stunned spectators.
It was a fitting way to mark 80 years of an institution which has provided adventures for generations of youths and, despite being in a landlocked city, is still going strong.
READ MORE: How can Sheffield tackle its growing problem of homelessness?
Her Majesty's Lord-Lieutenant Andrew Coombe and Stephen Ingram, the High Sheriff of South Yorkshire, joined armed forces veterans, community leaders and friends and family of the cadets on Monday, March 26 for what was the unit's biggest turnout in more than a decade.
The evening began in traditional fashion with a parade at the unit's new training centre on Rutland Road, in Neepsend, before the Royal Marine Cadets launched their sneak attack and their younger counterparts the Junior Sea Cadets induced more laughs with a specially composed song about their experiences with the unit.
The band then put on a captivating display, using illuminated drumsticks to add to the spectacle, and an evening colours flag ceremony concluded the formalities.
READ MORE: Ghost Stories set to chill moviegoers amid 'exciting' times for Sheffield's film industry
Chief Petty Officer Jack Martin, aged 74, was presented with his fourth medal clasp on the night for clocking up 35 years of voluntary service.
The unit's chairman, Councillor Terry Fox, said: "It has been a huge celebration for us all. In the last year the unit has grown to over 100 volunteers and we have an excellent new training centre with outdoor facilities and room to develop."
Mr Coombe, the unit's president, told cadets: "You are real ambassadors for our city, a huge credit to yourselves and the volunteers around you… and it's marvellous you are part of the campaign to name one of the Royal Navy's new Type 26 frigates HMS Sheffield."
READ MORE: Brave customers tackle knifeman during raid on South Yorkshire newsagents
Petty Officer Christopher Smith urged more young people to consider joining the unit and taking advantage of the life-changing opportunities if offers, from sailing trips in far-flung destinations to the chance to gain valuable new skills and qualifications.
* To find out more, drop in to the unit's Falkland Training Centre at the top of Rutland Road, which is open Mondays and Thursdays from 7pm-9pm, or visit www.sea-cadets.org/sheffield/sea-cadets.