What does the term "no-decompression limit" (NDL) refer to in diving?

The term "no-decompression limit" (NDL) refers specifically to the maximum time a diver can spend at a certain depth without needing to conduct a decompression stop during ascent. This is critical in diving as exceeding the NDL can increase the risk of decompression sickness, which occurs due to nitrogen bubbles forming in the body if a diver ascends too quickly after spending time at depth.

In practice, dive tables and computers help divers determine their NDL based on their depth and the specific gas they are breathing. Staying within the no-decompression limits allows divers to ascend directly to the surface safely, minimizing the potential health risks associated with rapid pressure changes.

Other options, such as the maximum depth a diver can reach or the total dive time allowed without breaks, do not accurately define the NDL concept. The NDL is not about establishing a minimum safety time post-dive either, but rather about safe ascent procedures during a dive itself. Understanding the NDL is essential for maintaining safety during recreational diving activities.