Understanding Decompression Theory and Tables is a core module for commercial divers and dive supervisors. It develops the knowledge and practical understanding required to apply decompression theory, interpret decompression tables, and manage diver safety during repetitive and staged decompression diving operations.
Decompression principles are critical for preventing decompression illness (DCI) and supporting safe operational planning. This module explains how inert gases behave in the body, how nitrogen is absorbed and eliminated, and how decompression models use tissue half-times to predict safe limits. It also introduces decompression procedures used in SCUBA and surface supply operations, including contingency planning and emergency response actions.
The module includes altitude diving corrections, diver monitoring responsibilities, the use of decompression computers, omitted decompression procedures, and emergency oxygen and post-dive flying considerations. Learners also explore different modes of decompression, including no-stop diving, in-water stage decompression, surface decompression, saturation decompression, and hyperbaric/recompression treatment.
Key areas covered include:
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Core principles and terminology of decompression theory
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Gas solubility, transport, and elimination in the human body
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Tissue groups and residual nitrogen concepts
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Decompression procedures for different diving systems
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Risk factors and predisposing conditions for DCI
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Decompression tables, repetitive diving, and dive profile limitations
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Altitude diving corrections and adjustments
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Diver monitoring, operational logging, and computer use
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Omitted decompression procedures and emergency oxygen response
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Flying-after-diving guidelines and decompression modes
By the end of this module, learners will be able to interpret decompression tables and profiles, apply safe decompression procedures, monitor divers effectively, and respond correctly to emergencies related to decompression illness and omitted decompression.
Course Features
- Lectures 40
- Quizzes 11
- Duration Lifetime access
- Skill level All levels
- Language English
- Students 226
- Certificate Yes
- Assessments Yes
- 13 Sections
- 40 Lessons
- Lifetime
- Introduction1
- Basic Decompression TheoryObjective: Develop the knowledge and practical understanding required to explain decompression principles and how inert gas behaves during and after a dive.
Knowledge: Explain basic decompression principles including tissue groups and half-times, saturation, in-gassing and out-gassing, residual nitrogen, and the limitations of decompression models.
Skills: Demonstrate decompression understanding by applying principles to dive examples and identifying how tissue loading influences decompression risk and planning decisions.8 - Terminology1
- Decompression ProceduresObjective: Develop the knowledge and practical skills required to describe and apply decompression procedures used in SCUBA and surface supply diving operations.
Knowledge: Explain types of decompression procedures, decompression rules, contingency planning, toolbox talk requirements, and decompression equipment used during operations.
Skills: Demonstrate operational readiness by applying correct decompression procedures and contingency decisions to dive planning and scenario-based emergency situations.7 - Predisposing Factors of DCIObjective: Develop the knowledge and practical skills required to recognise and manage factors that increase the risk of decompression illness.
Knowledge: Explain environmental, operational, and personal risk factors that contribute to DCI and how these factors increase decompression stress and risk exposure.
Skills: Demonstrate risk control decision-making by identifying predisposing factors in scenarios and applying preventative strategies to reduce decompression illness risk.4 - Decompression TablesObjective: Develop the knowledge and practical skills required to interpret decompression tables accurately and understand their limitations for different dive profiles and conditions.
Knowledge: Explain how decompression tables are structured, how no-decompression limits work, how repetitive dive rules apply, and how profile limitations affect table reliability.
Skills: Demonstrate table competence by selecting correct table entries for dives, interpreting repetitive dives, and identifying when table limits require modified planning or additional safety margins.5 - Dive ProfilesObjective: Develop the knowledge and practical skills required to interpret dive profiles and apply profile planning principles to decompression decision-making.
Knowledge: Explain what dive profiles are, different profile types, how profiles influence decompression requirements, and why certain profiles increase decompression risk and table limitations.
Skills: Demonstrate dive planning competence by identifying profile types and applying appropriate planning decisions and limitations to scenario-based dive examples.4 - Altitude DivingObjective: Develop the knowledge and practical skills required to understand altitude diving and apply corrections for safe decompression planning at higher elevations.
Knowledge: Explain altitude diving principles, how reduced atmospheric pressure affects decompression, required correction calculations, and how altitude influences equipment and operational planning.
Skills: Demonstrate competence by applying altitude correction procedures, adjusting dive plans accordingly, and identifying risks associated with altitude-related decompression errors.4 - Diver MonitoringObjective: Develop the knowledge and practical skills required to monitor divers and record dive information to support decompression safety and operational control.
Knowledge: Explain diver and self-monitoring requirements, buddy monitoring, post-dive observation, operational dive logging, and the role of decompression computers in recording profiles and exposure.
Skills: Demonstrate monitoring competence by applying correct monitoring procedures, recording accurate dive log data, and using computer information to support safe post-dive decisions.5 - Omitted/Failed DecompressionObjective: Develop the knowledge and practical skills required to respond correctly to omitted decompression incidents and apply emergency oxygen procedures during decompression-related emergencies.
Knowledge: Explain omitted decompression causes, risks, and response procedures, and explain why 100% oxygen is used for suspected decompression illness and how it supports casualty management and escalation.
Skills: Demonstrate emergency response competence by selecting correct omitted decompression actions, applying monitoring and escalation steps, and integrating emergency oxygen procedures into scenario-based emergencies.3 - Flying After DivingObjective: Develop the knowledge and practical skills required to apply safe flying-after-diving guidelines to reduce decompression illness risk after diving exposure.
Knowledge: Explain post-dive flying risks, why altitude exposure increases DCI risk, and the guidelines and time considerations for safe flying after diving.
Skills: Demonstrate safe decision-making by applying correct flying-after-diving rules to dive scenarios and selecting appropriate post-dive time and safety recommendations.2 - Modes of DecompressionObjective: Develop the knowledge and practical skills required to understand and describe different modes of decompression used in commercial diving and treatment environments.
Knowledge: Explain decompression modes including no-decompression diving, in-water stage decompression, surface decompression, saturation diving, and recompression/hyperbaric treatment, and when each is applied operationally.
Skills: Demonstrate applied understanding by identifying appropriate decompression modes for operational scenarios and explaining why specific modes are used based on depth, exposure, and operational requirements.6 - Final Exam1
