What is the primary purpose of wearing a life jacket on a boat?

Wearing a life jacket on a boat is primarily about safety, specifically providing buoyancy and flotation in case of an emergency. Life jackets are designed to help keep a person afloat in the water, significantly increasing their chances of survival if they fall overboard or if the boat capsizes. They are engineered to support the head above water, allowing the wearer to breathe and potentially signaling for help.

While life jackets can have secondary benefits, such as providing some warmth in cool water and offering protection from sun exposure by covering parts of the body, these are not the main reasons for wearing them. The primary function is to ensure that individuals remain buoyant and can keep their heads above water until rescue or until they can safely get back to the boat. This life-saving aspect is crucial and is why the correct answer emphasizes their role in providing flotation during emergencies.