I'm about 5'8" and weigh about 145Lb, and wear a size ten shoe. I figure the plans for a paddle blade in Nick Schade's book should be about right for me since I'm right at the mean geometric proportions. BUT, my wife is 5'2", around 105Lb, and size 6 shoe. Would it be wise to scale down the paddle blade's planform about 5% or 10%? Are there any guidelines to use for such a proportion adjustment?