Which type of divers need to be especially cautious about their ascent rate?

Deep or technical divers need to be especially cautious about their ascent rate due to the increased risk of decompression sickness and nitrogen narcosis associated with deep dives. These divers often operate at depths where the partial pressures of gases, particularly nitrogen, become significantly elevated, leading to a greater accumulation of inert gases in the body tissues.

During ascent, it’s crucial to adhere to recommended ascent rates and safety stops to allow for the gradual elimination of nitrogen from the tissues. This meticulous control of ascent rates helps prevent bubbles from forming in the bloodstream, which can result in serious injury or fatalities. Adopting a slow and controlled ascent enables divers to safely off-gas nitrogen, significantly minimizing the risk of decompression sickness, which is a concern amplified at greater depths.

While recreational divers also need to be mindful of ascent rates, their dives typically involve shallower depths and shorter durations, which do reduce the associated risks. Freedivers, too, need to be cautious but primarily face different risks related to shallow water blackout, rather than decompression sickness. Surface support divers generally operate at the surface and are less affected by these considerations, making them less concerned about ascent rates compared to deep or technical divers.