Bring your 9 & 13. Perth doesnt get constant big wind every day, you may be able to play on the 13 and change down to 9m if the seabreeze comes in properly. The key to the Perth seabreeze - is a 5-10 knot Morning South Easterly... the wind will crank the Sth westerly if this happens, and youll only need the 9m. If its S/E 15-20 knots, the breeze will be lighter.
Same rules as swimming beach - no kiting the swim area and kiting is the North side of car park.
If you tack upwind... youll see plenty of blokes walkin round with there tackle out

nudist beach