TDI Technical Diving

TDI Helitrox Diver Course

Learn to use helium deliberately to manage narcosis during staged-decompression diving. Helitrox develops gas selection, decompression planning, equipment management and team procedures for dives to a maximum of 45 metres.

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Course at a Glance

Minimum age18 years

ExperienceAdvanced Nitrox and 50 logged dives

Training4 dives; 2 deeper than 30 metres

Gas and depth limitsMaximum 45 metres; ≤35% helium and ≥21% oxygen

Who This Course Is For

Advanced Nitrox divers ready to introduce helium into decompression diving.
Divers seeking an alternative to deeper air diving within the Helitrox scope.
Divers progressing toward Extended Range, Trimix or advanced wreck training.

Prerequisites and Readiness

Minimum age 18.
SDI Advanced Diver with Deep specialty, TDI Intro to Tech Diver, or equivalent.
TDI Advanced Nitrox Diver or equivalent; it may be completed concurrently.
Proof of at least 50 logged dives.
Readiness for staged-decompression training and stable core technical skills.

How Training Works

The course includes at least four open-water dives, with two dives deeper than 30 metres, and progresses to a maximum depth of 45 metres. Academic and planning sessions address helium, decompression, equipment and contingency management.

Course duration is performance-based. Meeting minimum attendance or dive numbers does not guarantee certification; all required knowledge and skills must be demonstrated consistently.

Skills and Knowledge

Plan helitrox staged-decompression dives and select suitable gases.

Apply oxygen, nitrogen and helium exposure limits.

Analyse, label and positively identify breathing and decompression gases.

Complete gas switches, stops and ascents with precise buoyancy and team communication.

Manage simulated gas loss, equipment faults and decompression contingencies.

Maintain appropriate trim, propulsion, awareness and decision-making at depth.

Continue Your Development

Technical capability is developed through deliberate practice and experience between formal courses. Your next step should reflect your recent diving, equipment configuration and objectives.

TDI Extended Range TDI Trimix CCR Training

The Blue Water Ascent approach

Competence Before Certification

We coach understanding, judgement and repeatable performance—not minimum-standard completion. Training is adapted to the diver while every certification requirement and course limit is preserved.