Lost Garmin Oregen GPS

Hi, I was referrred here by someone in my walking group as you may have some knowledge of the area.
I was hiking around Garigal national park yesterday up around the Belrose supercentre down to forestville and my gps fell off my backpack somewhere near the start of the walk.
It must be somewhere along five mile creek or along the fire trail where it turns onto the tarmac bit.
If anyone finds it could they please reply to me here and there is a 6-pack in it for the finder.
Thank you.