Shark 150 is a great board for 16-30 mph winds for your size.
Thin in the back, slight fsw rocker, and narrow tail for it's with and heavy weight.. a great medium high wind flattish water board for big guys.
At 150 lbs., it's best for 17-25 mph winds and flattish water...but my 90liter boards plane sooner.
It says on the side of the board for 6.5-9.0 sails.... How in the world can I use it in 30 mph... I tried.. It was a disaster
Eddie
Those numbers are guidelines for the avg 65-75 kg windsurfer. The numbers make sense for someone that size.
Wait until you start sizing wet suits...