A kayak is a long, narrow, light boat, most often for one person, sometimes for two. You sit down inside it with your legs out in front, and you move it with a paddle that has a blade at both ends — one left, one right. The top of the boat fits around you more closely than a canoe does, so splashes are less likely to fill it. People take kayaks out on lakes, rivers, and the sea, for fun, for sport, and, in the past, to hunt. The word is also a verb: to kayak means to travel in one of these boats. It is ordinary English, not formal. The boat is not the same as a canoe, though people mix the two: in a canoe you often kneel or sit higher, the boat is more open, and the paddle usually has only one blade.