To rest comfortably on the surface without having to tread water, you always must:

Establishing positive buoyancy at the surface is crucial for resting comfortably while diving. When a diver achieves positive buoyancy, they naturally float and can maintain a relaxed position without expending energy to stay afloat. This buoyancy allows the diver to conserve air and stay calm, which is essential for monitoring one’s surroundings, communicating with dive buddies, and managing air supply effectively.

Remaining still and breathing slowly can be helpful in maintaining buoyancy, but without achieving positive buoyancy first, these actions alone may not prevent sinking. Signaling a buddy for support is a valuable action, but it does not address the fundamental need for buoyancy. Similarly, while a flotation device can aid in buoyancy, divers often practice achieving it naturally through proper technique and weight management, which are foundational skills in diving. Therefore, establishing positive buoyancy is the key factor in resting comfortably at the surface.