This boom boat is displayed in the Naval Heritage Museum on Garden Island.
On the last day of May 1942, it was rowed by James Cargill and William Nagle as they went about their job of ensuring that the boom and net that stretched across the inner harbour was intact. Midget Japanese Submarines were known to be targetting Sydney Harbour.
At 9:51pm it was confirmed that the 'object' sighted 90 minutes earlier was, indeed, a midget sub, but before it could be attacked, the two Japanese submariners, blew their vessel to kingdom come.
I wanted to show you where the Boom was located but Google Map only gave me an option of Car or Foot, when I wanted to row! The boom and net went across the water from A to B. The sub was trapped close to B.
The two Japanese submariners were Lt Kenshi Chuman and Petty Officer Taeshi Omori.