Chosing correct size diving board - help plz

Hopefully this is in the appropriate section... Trying to figure out if I need a 6' or 8' board. There are already stands, the upside down U style mounted in the deck of our IG pool. It's a kidney shaped pool, with 8' deep end. The mount farthest from the pool is 5' away, so a 6' board would be over less than a foot of water, while an 8' board would be a little less than 3'. I've searched this site and google & can't find any rules about this. Thanks for your help!

http://www.srsmith.com/residential/p..._standards.pdf

They also have a toll free CS number where they can help you.