Hey Hobartsup, there is a SUP race at the Carlton Surf Festival on 5/12, they are looking at 2 divisions, 1 for surf sups and one for 12'6", it will be run on a "technical race" style course as far as I know, check the "TassieSUP" facebook page as more details come to hand.
also Park Beach Boardriers Club are running a SUP surf and Race comp 22/11
And let's no forget the "Carlton River 10" race/social paddle 28/11