Saturday & Sunday at North end of Umina Beach. High tide doesn't peak until 3:20pm with a delay of 30 mins at Ettalong so the flow into Brisbane water will take a while to turn and head back out. A Nor' Easter gets compressed around the headland when it works and it's a pretty special place with very flat water and small ramps.
Unfortunately I can't make either day but I hope someone checks it out and reports back.