Double concave lesson required

Hi. I’m pretty new to the game Can somebody please give me the lowdown on double concave. I’m building a 6’9" for a friend and he wants a double concave. I’d like to know a bit more about it before I start shaping… What will it do for the board And a brief description of how I should shape it Thanks Brian (Ireland)

have you looked in the archives ? also, here is a good intro- http://www.pipedreamsurfboards.com.au/100817.php brian http://www.pipedreamsurfboards.com.au/100817.php