This has be my favourite plaque I've found so far.
The plaque reads:
'In Memory of Harold Edward Holt, P.C., C.H.,
Prime Minister of Australia from 26.1.1966 until 19.12.1967. He disappeared while swimming of Cheviot beach during rough weather on 17.12.1967.'
The accompanying tableaux provides background:
'On 17 December 1967 Prime Minister Harold Holt went missing after swimming in the waters below at Cheviot Beach.
He was a keen swimmer and snorkel diver who owned a holiday house in nearby Portsea. Cheviot Beach was out of bounds to the general public but under special arrangement with the Department of Defence Harold Holt would swim these chilly Bass Strait waters he knew so well.
Accompanied by four friends he went for a quick swim before lunch and shortly after it was realised the Prime Minister could no longer be seen.
Australia's biggest search operation to that date took place but Harold Holt was never seen or heard from again. The disappearance created world headlines and fuelled multiple conspiracy theories including abduction, assassination and suicide. [There was a theory he was taken by a Chinese submarine].
What the plaque also fails to mention is that there is a Melbourne swimming pool named after him.
Submitted by: @IanThorp