Hey Flipper,
Shearwater is awesome when the tide is right in a SE wind, it seems to get the most wind on the goldie when it's southerly. However if the tide is going the wrong way you'll want to be planing and know how to go upwind 'cos otherwise you'll be doing the big long walk back up the beach. Tide will be right after about 1pm on Saturday for the shearwater.
I'll probably be down at Coolangatta / Tweed though, if it's not right for the alley then it will be good for the golf course in the morning. The wind needs to be pretty much 20 knot SE for the alley to work well imho, I've spent many hours floundering around trying to dodge surfers when it's not right.
Speaking of the alley, the triathlon is where you get munched in the shorebreak near Palm beach and can't get back out, have to walk your gear back to the seawall, swim it across the river/estuary there, then carry it back to your car. Or do what I did once, leave your gear on the beach and drive round to pick it up