This thread makes crossfit seem like a joke.
A bunch of guys in a warehouse near one of my offices claim they do crossfit, and they are a group that really puts a smear on the crossfit label.
every time I see them I have the weirdest thought- they look like they are trying to accomplish the "feats of strength" portion of Festivus.
I am in a similar situation as you are- I need to maintain strength for wakeboarding, but any extra pound is a no-no.... the knees and lower back take a beating.
Over the years I just cobbled together a workout routine that focused on core strength and leg strength. weight wise, I do 4 sets of 20+ reps for pertinent muscle groups, keeping the weight lower and using slow, controlled lifts.
Food is the most important part... low fat,minimal sugar, keep the calories at about 2000-2200 a day when I work out, and I keep protein to a gram for every pound and a half to 2 pounds of body weight.