Complex sentence: A kneeboard is a good piece of equipment to start out on for boat-towed sports--the low center of gravity often makes it easier to get up on than a waterski or wakeboard, which both require standing up.
Split into simpler sentences: A kneeboard is a good piece of equipment to start out on for boat towed sports. The low center of gravity often makes it easier to get up on than a waterski or wakeboard, which both require standing up.