Why are bubbles a critical underwater signal for divers?

Bubbles are a critical underwater signal for divers primarily because they signal that someone is beneath the surface. When divers exhale while submerged, the bubbles they produce rise to the surface. This visual cue informs boats and other watercraft that there is an individual underwater, allowing them to take necessary precautions to avoid accidents, such as maintaining a safe distance or being aware of the diver's location.

While bubbles may attract fish, this is more of a biological interaction rather than a direct signal related to diver safety. Similarly, while bubbles can indicate various conditions, they don't specifically denote the need for assistance, as divers typically use other signals (such as specific hand signals) for that purpose. Additionally, bubbles are not an indication of impending bad weather; instead, they are a natural byproduct of a diver’s breathing while submerged. Understanding the importance of bubbles allows divers to enhance safety measures in their aquatic activities.