What is the primary purpose of a life buoy?

The primary purpose of a life buoy is to provide a flotation device for rescuing people. Life buoys are designed to assist individuals who may have fallen overboard or are otherwise in distress in the water. When thrown to a person in need, a life buoy helps them stay afloat, preventing drowning and providing a means for rescue personnel to reach the individual more easily.

The buoy's design typically includes features such as bright colors and reflective materials to make it easily visible in emergency situations, ensuring that rescuers can locate and retrieve individuals quickly. The buoy is also equipped with a rope that can be used to pull someone back to safety or to secure the buoy to a point of reference, further facilitating a safe rescue operation.

Given that the other options do not accurately reflect the primary functionality of life buoys, their purposes are secondary or irrelevant in the context of personal survival techniques at sea.