hi bill,
low tide tomorrow is just after midday.
plev is right. it's a great spot to windsurf regardless of tide.
at high tide there is still lots of flat water around, especially at the western end. the bumpy bits are between the eastern end of Thomsons and the strip and best at high tide.
at low tide the strip is dead flat. even in 30knots close to the bank is like glass because the bank sticks about 10-20cm above the water. at low tide the water right beside the bank is 2m deep. the flat water continues for about 1km. also at low tide most of the place is flat cause there are lots of sandbanks that kill the swells.
i reckon tomorrow is our best pick this month for speed.

if you come tomorrow park at the eastern end. that is the best place to launch from at low tide. you just walk about 100m across sand and launch straight into the channel.
at high tide most park at the western end. there are maps and stuff on the wanderers website in the locations guide.