Hi Grumps, thanks for your sighting. It looks like the location information you provided is incorrect. This can occur if the GPS sensor in your device was having a bad day. Please review and update the location of this record when you get a chance.
I'm pretty sure not a megabat. I'm guessing a Gould’s Wattled Bat (Chalinolobus gouldii) because it was hawking over water, in full daylight and about the right size and colouring. Have put that in as an ID, but looking forward to an informed ID from someone knowledgeable.