What does the "three-minute rule" in diving entail?

The "three-minute rule" in diving specifically refers to the recommendation for conducting a safety stop during ascent. This rule suggests that divers should pause their ascent for a period of about three minutes at a depth around 15 to 20 feet (approximately 5 to 6 meters) after completing a dive.

The purpose of this safety stop is to allow nitrogen that has built up in the body during the dive to safely off-gas and reduce the risk of decompression sickness, commonly known as "the bends." By taking this time to ascend slowly and stabilize at this depth, divers can mitigate the potential for nitrogen bubbles forming in the tissues, which can happen if they ascend too quickly without allowing enough time for the body to equilibrate.

Other options, such as ascending rapidly, performing decompression stops, or ruling dive equipment checks, do not align with the principles of safe diving practices as outlined by the diving community. Ascending rapidly can increase decompression sickness risk, while decompression stops are specifically required for dives beyond no-decompression limits, and dive equipment checks are essential regardless of the dive but are separate from the context of ascent safety.