formula hwr or lwr

[cienvolando]

First of all, congratulations for being an escential part of the future of windsurfing. I sold my formula 160 and I want to buy one of the 2010 formula models and I have two doubts:
1) After analizeing the information available at http://www.star-board.com/2010/produ...rd_formula.php there are two boards to choose, I need to know what a medium weight raider means in kg aprox. If I knew the weight of what the formula 2010 web page refers as a midium weight rider, It would be easier for me to choose the correct board.
2) I see ilogical that the that the LWR, which is intended for medium to light riders, has more volume (168) than the HWR (162) which is intended to heavy weight riders. I´m not a designer, but perhaps there is an error in the information provided in the formula 2010 web page because I believed that more volume is intended for a heavier rider and viceversa.
I´ll be waiting for your reply,
Regards.