Decompression diving

Technical diving past no-decompression limits, where mandatory staged stops on the ascent become a ceiling you cannot safely cross.

Decompression diving means intentionally exceeding the no-decompression limit, so that mandatory decompression stops stand between you and the surface. The accumulated inert gas in your tissues creates a ceiling: ascend past your required stops and you risk decompression sickness. That single fact changes everything, because a direct ascent, the recreational safety valve, is no longer available, making deco diving a technical discipline by definition.

A decompression dive is planned in software or on a computer running an algorithm, often with gradient factors tuned to taste, and executed as a schedule of staged stops that get longer as you get shallower. Most deco divers accelerate the shallow stops by switching to a richer deco gas, commonly EAN50 or pure oxygen at 6 m, carried in clearly marked stage bottles. Redundant gas, a backup computer, and DSMB and spool for drifting stops are baseline equipment, and gas planning follows rock-bottom logic with fat reserves.

Training runs through technical agencies and courses like TDI Decompression Procedures or GUE Tech 1. The reward is time: on wrecks and walls at 40 m and beyond, deco turns a 10 minute bounce into a real dive. The price is discipline, since every minute deeper is paid for on the way up. Start with conservative profiles and grow the exposure slowly.