ON a grey morning on April 1, 1978, an iceberg floated into Sydney Harbour.

Talkback radio went into meltdown as hundreds of callers jammed the switchboards to report the bizarre sight. People headed for the harbour, boats were launched and for several hours, the media provided a blow-by-blow account of the scene.

Then it started raining, the iceberg ‘melted’ and Sydney’s most elaborate April Fools hoax was revealed.

The prank was the brainchild of 34-year-old electronics entrepreneur Dick Smith.

media_camera A young Dick Smith with the April Fool's Day front page about him in 1978..

Smith had been telling the media for months that he would float an iceberg from Antartica as an experiment to provide fresh water to drought-prone areas.

He had promised to carve it into small ice cubes and sell them as ultra pure “Dicksicles”, which he said would improve the flavour of any drink.

Enlisting help from several mates and 300 Dick Smith staff, Smith hired a barge, and using a huge white sheet, fireman’s foam and shaving cream, created the iceberg — christened the ‘Dickenberg One’.

The iceberg had been built before dawn. Fellow inventor Hans Tholstrup had towed the barge out through the Heads around 3am and the conspirators went to work.

When it sailed into the harbour, Smith’s staff began calling every radio station and the city was duped.