There might be sand at Cooks Beach - but I have been scanning the distance carefully to pick up all the distinctive landmarks and I would suggest the skyline is more akin to the view from the Friendly Beaches or Bay of Fires than from Cooks.
In fact, I think I have been able to rule out any of Tassie's lakes as well

Edit - trying to be serious - most of the white beaches I know in the NE have rocky points jutting out rather than sand.
This suggests it is near a river/lagoon outelt in order to build the sand bar.
Perhaps Policeman's Point? [2nd edit - Google Satellite even shows a similar seaweed pattern - and it is from a tastrax helicopter...]