Decompression strategies

Different decompression strategies balance planning, flexibility and workload. Here is a brief comparison—and why Ratio Deco is our preferred approach within its limits.

Run-time profiles

A written schedule tells you when to leave each stop.

Benefits: Clear, easy to share and useful for gas planning.

Drawbacks: Limited flexibility. Changes to depth, time or available gas require appropriate contingency plans.

Computer diving

Your computer calculates decompression throughout the dive. Algorithms include Bühlmann ZHL-16C, commonly used with gradient factors, and alternatives such as VPM and RGBM.

Benefits: Tracks the actual profile and updates decompression requirements.

Drawbacks: Results depend on settings and correct gas selection. Team members may receive different schedules, and following a display can encourage passive decision-making and those theoretical models can give incorrect results. Additionally all electronics underwater will fail eventually!

Ceiling-controlled decompression

You gradually ascend with the computer’s moving decompression ceiling, staying at or deeper than that limit.

Benefits: Can reduce calculated decompression time compared with fixed stops.

Drawbacks: Requires precise buoyancy and close attention. Shorter decompression has not been established as safer.

Ratio Deco

Trained divers use rules relating depth and bottom time to estimate decompression within defined limits.

Benefits: Supports a shared team plan, mental cross-checks and adjustments within its trained range. Forces the diver to actually plan the dive and follow the plan within a certain degree of flexibility rather than blindly follow a computer.

Drawbacks: Requires specific training and standardised gases. 

We prefer Ratio Deco for the active involvement and team understanding it encourages. That is a practical preference, rather than a claim that it is universally the safest choice.