Evening Shaun,
If you notice, when you open the pop-up box for each vessel, there is a small notation that refers to a number like VK2 THK (which is actually my ham call sign) and this is the call sign of the ham operator who is monitoring AIS and posting the results on-line. There are blank spots, as it is necessary to have a few ham operators scattered along the coast to get full VHF coverage of Australia. We are lucky that most of the eastern seaboard is covered except for northern Queensland.
Phillip
SEAKA.
PS Shaun, The bar was terrible just on dusk with 2m waves across the full width! Not a day to be outside
!