When I saw a demo, they had an easter egg of a Loch-Ness type monster in it.
There's also a topographical map of the harbour at St Ives showground but it's purely non-hydrographical. But it's almost disappeared now through neglect.
Meanwhile the Soviets probably found a little inlet somewhere that was "close enough", evicted anyone who lived there and excavated it to match.
Some junior engineer probably had to wake up at 1am to take a kayak out to "Little Kotlin Island" to change the tape in the recording equipment in time for the tide change.
It's actually a topographical map of the whole Sydney basin.
This article has a pic: https://www.neighbourhoodmedia.com.au/post/st-ives-showgroun...
[edit: Seems to be where the RC cars race!]
Another page on that site mentions Eben Gowrie Waterhouse OBE CMG (1881–1977) ... while he is known for Camellia cultivation my research suggests he met with Mussolini and the Japanese government around war time and was a bit of a fascist. They don't mention that bit.
And sure enough: https://www.eryldene.org.au/
Interesting guy: https://en.wikipedia.org/wiki/Eben_Gowrie_Waterhouse