Kayak paddles comprise dual blades, whereas, canoes use single blade paddles. There's the sea or ocean kayaking, which involves using the kayak out to the seas or open water (lake). Taking the kayak down the rapids is called whitewater kayaking. It is actually popular among adventureenthusiasts and divers, etc. It's much better to be aware of some basics, just before entering a kayak. The very first important point out note is the fact that power in paddling is generated from the torso (trunk) and then channeled through the biceps and triceps.