What is necessary for a diver to monitor during the ascent phase?

During the ascent phase of a dive, it is crucial for a diver to monitor depth and ascent rate. This is because ascending too quickly can lead to decompression sickness, commonly known as "the bends." By maintaining a controlled ascent rate, typically recommended at no more than 30 feet per minute (or 10 meters per minute), a diver allows for sufficient time for nitrogen to safely leave their body, which minimizes the risk of the bends.

Monitoring depth is also important because it helps divers keep track of their ascent profile and ensures that they stay within safe depth limits throughout the ascent. Understanding both the depth and progression of ascent allows divers to adhere to safety stops, which are essential for allowing additional nitrogen to off-gas from the body before reaching the surface. This practice is a fundamental safety measure in diving, emphasizing the importance of careful monitoring during ascent.

In contrast, while oxygen levels, ambient temperature, and equipment malfunction are all relevant to diving safety, they do not directly pertain to the critical factors that need monitoring specifically during the ascent. Focusing on depth and ascent rate during this phase is essential for preventing potential physiological risks associated with diving.