Good Samaritans have my wet surf gear, contact???

I need some help.

I finished a kitesurf session at Cylinder Beach North Stradbroke Island today and accidentally left my wet boardies, long sleeve 2mm wetsuit top and a Quiksilver vest on a BBQ table where a nice Kiwi fellow and his Brazillian girlfriend (lucky guy) were having lunch.

I raced to catch the bus back to Brissie (1pm) and they actually helped me carry my gear (in light rain) to the bus stop as I was late and only once home and unpacking, I realised I had accidentally left the wet gear on the BBQ table.
I called the nearby coffee shop owner whom had served me this morning and he checked the spot (again in the rain) approx. 2 hours later and the gear was gone.

How on Earth can I contact/find these two as they were great to talk to and I am sure they simply kept the clothes and are thinking the same as I, how to return the gear to the owner, me!

The guy was smaller than me and not a surfer-type so probably had little use for the clothing.

Any advice appreciated.

Cheers.

Yep I have pretty much given up on the gear being returned but I know nothing about facebook/instagram and was wondering if there is a general area where you can say, " Hey, looking for Joe Blow" etc. and see what happens?

brazilian girlfriend , ahhh that would be brazilnuts , leoloro whatever he calls himself this week

ya gotta watch that place especially around the BBQ picnic area.
just the other day i was having lunch with my hot Brazilian girlfriend when this kitesurfer kept eye Farking my girl.
lets just say i fixed him up.