I was down at a local site recently with side-on winds. One of the kooks had a windmeter and rather than stand there like the Statue of Liberty, he put it atop a stick about 7 ft high in the sand.
It was reading 7-9 knots with occassional (very) gusts to 12.
I (175lbs.) was fully powered with a 14m kite on a 135 x 40cm board. Ok, the board is wide, but there is no way it was 8 kts.
8kts on the beach at 7ft elev. is not the same (true) reading as the reading 50m out into the ocean at 7ft- or really, 50m out at 27m high.
The wind reading on the beach is therefore a relative number and not absolute. That is, its not 8kts and no one should delude themselves that it is. Its semi-useful because I now I know I can sail in "8kts" (according to the meter) but it ain't 8 knots. I also know that when it picks up to "15" I can put on my 10m!
With all due respect to the posts from the 19.5 Contra (for example) sailors who are blasting in 6 knots- I'm happly you are out there but I doubt its 6, 8 or really much below 10-11kts.
That is all.