How deep can you dive without decompression?

As a diving expert with extensive knowledge in underwater exploration, I can tell you that the depth you can dive without needing decompression stops is determined by various factors, including the type of gas mixture you're breathing, your physical condition, and the duration of your dive. For recreational divers using air as a breathing gas, the general rule of thumb is the "10/3/3 rule", which suggests that for every 10 meters (33 feet) of depth, you should allow 3 minutes of decompression at 3 meters (10 feet) before ascending to the surface. This rule is a simplified approach to managing decompression obligations and is not a substitute for proper training and dive planning. However, when we talk about technical diving, divers often use nitrox (a mix of nitrogen and oxygen) or trimix (a mix of helium, nitrogen, and oxygen) to extend their bottom time at greater depths. With these gas mixtures, divers can often stay down longer before needing to perform decompression stops. The reference to a diver being able to dive for many hours at 6 meters (20 feet) without needing decompression stops is accurate for recreational diving. At depths greater than 40 meters (130 feet), the time before decompression stops are required is significantly reduced, often to just a few minutes. It's important to note that these are general guidelines and actual safe diving practices require adherence to specific dive tables, dive computer algorithms, or proper dive planning techniques based on the type of diving being conducted.

A diver at 6 metres (20 ft) may be able to dive for many hours without needing to do decompression stops. At depths greater than 40 metres (130 ft), a diver may have only a few minutes at the deepest part of the dive before decompression stops are needed.