TDI Advanced Trimix Diver

Course Overview & Training Objectives

TDI Advanced Trimix Diver is the terminal open-circuit technical qualification for deep-ocean exploration down to 100m (330ft). The curriculum examines the physiological hazards of extreme depth, including hypoxia, isobaric counterdiffusion (ICD), HPNS, and hypercapnia under increased gas density. Divers train to manage multi-stage decompression profiles using travel gas, custom trimix bottom mixes, and accelerated pure oxygen staging.

Operational Envelope

• Max Depth: 100m (330ft)
• Decompression: Unlimited accelerated deco
• Breathing Gases: Hypoxic Trimix bottom gases (<18% O2); appropriate travel gases and at least 2 to 3 deco stages with up to 100% O2
• Equipment Rig: Double + 3+ Stages

Course Structure & Training Requirements

• Course Duration: 4 to 6 Days
• Required Training Dives: 4 in-water dives
• Classroom & Theory: 16 hours instruction

Entry Gates & Prerequisites

Min age 18, 150 logged dives