Personally, I think kickboards are evil, evil, evil. When I was swimming 20 years ago in high school I didn't see the point, and now that I'm 38 I still don't see the point.
Happily though, I've read in several books and seen on a few video tapes that many coaches have come around to my line of thinking, "Kickboards put you in an unnatural heads-up position, emphasize the least effective part of the stroke (the kick), and keep you from rotating."
Since I see people swim with kickboards every day I know many people disagree with me. But, there's no way they're going to change my mind. Instead - let's vote!
I just remembered another use for kick boards. This is a drill I read about,take 2 kick boards and put them under you at your center of buoyancy(lying prone in the water.)Start with your arms and legs spread for balance and the slowly move them together until you are in streamline position.Hold for 30 sec. When that gets easy go to 3 boards etc.The most I ever held for 30 sec. was 5.This is a good drill for balance,body position and core strength.It can also be done on your back.
I just remembered another use for kick boards. This is a drill I read about,take 2 kick boards and put them under you at your center of buoyancy(lying prone in the water.)Start with your arms and legs spread for balance and the slowly move them together until you are in streamline position.Hold for 30 sec. When that gets easy go to 3 boards etc.The most I ever held for 30 sec. was 5.This is a good drill for balance,body position and core strength.It can also be done on your back.