Why is it essential to monitor no-decompression limits during a dive?

Monitoring no-decompression limits during a dive is crucial primarily because it helps prevent excessive nitrogen absorption in the body. When divers descend deeper and for longer periods, nitrogen from the breathing gas dissolves into the body's tissues. Each dive has specific no-decompression limits based on the depth and time spent underwater, defining the safe confines within which divers can operate without needing to make staged decompression stops during ascent. If these limits are exceeded, the risk of decompression sickness, commonly referred to as "the bends," increases significantly. This condition occurs due to nitrogen bubbles forming in the bloodstream and tissues as atmospheric pressure decreases during ascent, which can lead to severe pain, long-term complications, and even death. Therefore, adhering to no-decompression limits is essential for ensuring a safe return to the surface without the need for emergency interventions or additional dive complications.