Cannot locate via normal search engine. I am sure your expertise in computing may come in handy. Rumour has it that it was developed by Aussie; consolidating data from all Marine/Fisheries Dept. and public utilities co. in the region; designed to be used in offshore construction project.
I briefly looked at google. I thought it was the Japanese one that leaked outside lately. Never mind, I'll keep on searching. This is something good to share.
Oh! Japnese again? I recalled a similiar situation happened before the WWII. They made a detailed map about HONG KONG which better than the British. Ha...ha..! Just kidding!