The Queen earned her junior respiration award in February 1941 and was one of the first young people in the Commonwealth to receive the accolade.
With the colour purple often being linked to royalty Her Majesty's choice in outfit could be a show of stoicism as reports confirm she has no plans of abdicating her throne anytime soon.
"I didn't realise I was the first one - I just did it, and had to work very hard for it," the Queen said in the video call.
"It was a great achievement and I was very proud to wear the badge on the front of my swimming suit.
"It was very grand, I thought."
When the Queen said it had happened "a long time ago," deputy Commonwealth president of the society, Clive Holland, said: "Your Majesty, when you say it was a long time ago, it was in fact 80 years ago."
To which the Queen quite hilariously responded: "That's terrible!"
Her Majesty also virtually presented the King Edward VII Cup to Stephen Beerman during the call in recognition of outstanding contributions to drowning prevention.
The video call marks the first appearance from the Queen since the funeral of her late husband. Prince Philip passed aged 99 on April 19 and was laid to rest on April 17 at St George's Chapel in Windsor Castle.
Attending the funeral alongside her family, The Queen was stoic and resilient as ever - even through the grief.