Just to add fuel to the fire, I believe the meters are quite accurate. If you pick a nil wind day and drive along in a car with the meter at arms length out the window with the screen on kph, it is remarkably accurate vs the speedo - even at 10kph.
I can only suggest 2 reasons for the "gap":
1) I'm told the Bureau uses meters on very high poles, and the wind is stronger at higher altitudes. At Garden Island for instance I'm told the anemometer is in the middle of the bridge, which must be 30 metres high at least. Also correlates with plane flights where the pilot comes on and advises the flight is late due to 150knt headwinds - don't get many of them at sea level !
2) You would all have noticed the wind is stronger 200m off the shore with the wind coming off the sea than it is on the shore. Again, we stand on the shore with our toys.
Anyway, it's still frustrating. It does however explain how you read in the English mags where they claim to go sailing in 10knt winds - when my windwatch shows 10knts I can get my Formula up, meanwhile SeaBreeze is showing 15knts +
kecksoff - spend your money on a bigger sail and then use the ageless rule - no whitecaps = no planing.