I've done it last two years but sadly away working this year. Wind was lightish both times in '14 and '15. Used a 17 Zephyr and a Mako 150. Needed every meter of kite and every cm of board.
Broad reach to slightly downwind both times with minimal swell and sea, BUT, its hit and miss this time of year so you might get a 25kn seabreeze on the day. That would be a very different crossing. Watch the forecast and pack your gear as close to the cutoff as possible.
Keep in mind wind is usually stronger at Rotto and will lighten as you get closer to the coast.
Good luck man, have a blast.

17 metre, wow! I thought Perth was supposed to be super windy!
Good to know the wind lightens up closer to the mainland.
Do you need your own lifejacket? Is that compulsory?
Cant wait.....

JoeMc said..
Ollie yes you need your own lifejacket but you will be issued with flares for the race. These are for use in the event you are attacked by a skark. Just shoot it into their mouth like they do in the movies.

I have a spot this year and have a choice of 7,9 and 12m kites.

Hoping for about 20 knots and loads of weed so the foilers fall over.

Joe, I hope you win the race just for that comment.