How Does a Kayak Stay Afloat?

Flotation

In order for any object to float, it must have a density that is less than the substance that it is floating in. An object with less density than water will float on water, while one with a greater density will sink.

Kayak Structure

Kayaks are composed of largely hollow, buoyant materials like plastic or fiberglass. The hollow construction means that much of the kayak's mass is composed of air, which is less dense than water. Overall, a kayak is less dense than water and will therefore float when put in a lake or river.

Balance

Another aspect that is necessary to a kayak's flotation is balance. This has to do with the kayaker--she must balance properly or the kayak will flip over. Learning proper balance takes some time and is one of the basic skills of kayaking.

Roll

Unlike many other boats and watercraft, kayaks will not sink if they capsize. Instead they are designed to rollover. In a maneuver called an eskimo roll, the kayaker can turn the kayak upside down and then back up for a full 360-degree roll. This is an important skill in kayaking particularly when using a sit-in kayak where underwater exit can be difficult. Most other types of boats are not able to roll over in this fashion and will begin to take on water and sink if they capsize.