Tec Trimix 65 – Normoxic Trimix Diver Course
Delivered by Ed Bosworth (Professional Diver Training) in partnership with Go2Similan Diving, Khao Lak
Course Overview
The Tec Trimix 65 course is your entry into the world of helium-based technical diving. This programme introduces you to the advantages of normoxic trimix, allowing safer and more controlled dives to 65 metres while reducing narcosis, improving mental clarity and extending bottom time when combined with accelerated decompression.
Under the expert guidance of Ed Bosworth, you’ll learn to plan and execute deep multi-cylinder dives using helium-based bottom gases, travel gases and high-percentage oxygen for decompression. Training includes multiple deep wreck dives supported by Go2Similan Diving’s experienced technical dive team.
This is the essential step for divers aiming to progress toward full hypoxic Trimix, expedition diving or advanced deep-wreck exploration.
What You Will Learn
Helium-Based Diving Theory
-
Advantages of normoxic trimix mixtures
-
Managing narcosis, gas density and work of breathing
-
Planning travel gases, bottom gases and decompression gases
-
Advanced decompression theory for deep profiles
Technical Skills & Gas Management
-
Gas-switching using multiple cylinders
-
Handling four to five cylinders depending on dive requirements
-
Rolling stages for complex multi-cylinder dives
-
Redundancy planning and bailout strategies
-
Long decompression stops and contingency procedures
Deep-Water Emergency Procedures
You will practise and master:
-
Managing gas loss at depth
-
Handling equipment or regulator failures
-
Out-of-gas protocols using travel and deco gases
-
Managing an unresponsive diver
-
Problem-solving during long decompression sequences
Open Circuit & CCR Options
Training can be completed on either:
-
Open Circuit configuration
-
CCR (Closed-Circuit Rebreather), where available
Course Dives & Structure
The Tec Trimix 65 course typically includes:
Day 1 – Checkout Dives
-
2 dives to confirm buoyancy, trim, equipment setup and emergency drills
-
Cylinder management practice
-
Gas-switching and deep-dive simulations
Training Dives
-
4–6 deep training dives
-
Minimum 2 normoxic trimix accelerated decompression dives
-
Deep wreck dives such as the Torpedo or other suitable 60–65 m shipwrecks (weather permitting)
Maximum Depth: 65 metres
Price
Tec Trimix 65 – 40,000 THB
Helium and sorb are not included.
Combined Tec Trimix 65 + Trimix 90 Package – 80,000 THB
Gas and sorb not included.
Prerequisites
To enrol in Tec Trimix 65, you must have:
-
Tec 50 certification (or equivalent)
-
Minimum age 18 years
A recent dive medical may be required.
Why Train With Ed Bosworth & Go2Similan Diving?
-
Expert-level deep technical instruction
-
Access to suitable deep wrecks for trimix-level training
-
Professional gas-blending facilities
-
Open Circuit and CCR options
-
Small student-to-instructor ratios
-
Real-world exposure to deep-water task loading and extended decompression
Frequently Asked Questions about Tec Trimix 65
What is the PADI Tec Trimix 65 course?
PADI Tec Trimix 65 is a normoxic trimix course that extends your depth range beyond Tec 50 while keeping narcosis and gas density under better control. You learn to plan and conduct staged decompression dives using trimix with a minimum oxygen content suitable for dives to 65 metres, plus one or more decompression gases.
Who is Tec Trimix 65 designed for?
Tec Trimix 65 is designed for experienced Tec 50 divers who are comfortable with decompression, multiple cylinders and technical procedures, and who want to extend their depth range and manage narcosis more effectively using trimix. It suits divers who want more flexibility for deeper wrecks, walls and big blue water dives without going straight to full hypoxic trimix.
How deep can I dive with Tec Trimix 65?
Tec Trimix 65 qualifies you to plan and execute trimix dives with a maximum depth of 65 metres, using normoxic trimix blends and one or more decompression gases. Training dives are always planned conservatively based on conditions, your experience and how you progress during the course.
What are the prerequisites for Tec Trimix 65?
You should hold a Tec 50 (or equivalent) certification, have recent technical diving experience, solid buoyancy and trim, confident gas-switching skills and be comfortable handling multiple stages. You’ll also need a suitable medical, dive insurance that covers technical depth and decompression, and to meet the experience requirements in the current PADI Tec Trimix 65 standards.
What will I learn on the Tec Trimix 65 course?
You’ll learn how to select and plan trimix gases for dives to 65 metres, manage narcosis and gas density, refine your emergency and problem-solving skills at depth, handle multiple stages and deco gases, run decompression profiles with backup plans, and work as part of an experienced technical team under realistic conditions.
How is Tec Trimix 65 different from Tec Deep or Tec 50?
Tec 50 and Tec Deep focus on air or nitrox-based decompression dives and give you the core skills of technical diving. Tec Trimix 65 adds trimix planning, deeper depth limits and more complex gas strategies, so you can manage narcosis and gas density more safely on deeper dives and build experience towards full trimix training.
Where does Tec Trimix 65 training take place?
Tec Trimix 65 training is based in Khao Lak, Thailand. You’ll do classroom sessions for theory and gas planning, then progressively deeper open water training dives at suitable sites where you can practice team skills, gas switches and staged decompression in real-world conditions.
What equipment do I need for Tec Trimix 65?
You’ll need a twinset or technical sidemount configuration, multiple stage and decompression cylinders, suitable regulators with proper hose routing and clear labeling, at least two independent computers or a computer plus bottom timer, reels and DSMBs, backup lights and exposure protection appropriate for depth and conditions. If you don’t yet own all of this, Ed can help arrange suitable equipment and advise on configuration.
Does Tec Trimix 65 prepare me for full trimix training?
Yes. Tec Trimix 65 is an ideal stepping stone towards full or hypoxic trimix courses. Once you are comfortable with trimix dives to 65 metres, moving on to deeper trimix levels becomes a structured, logical next step.
Certification Outcome
Upon successful completion, you will be qualified to:
-
Conduct normoxic trimix dives to 65 m
-
Plan and execute trimix accelerated decompression
-
Use multiple cylinders with helium-based bottom gas, travel gas and 100% oxygen
-
Progress directly into full (hypoxic) Trimix / Trimix 90 training
This course is your gateway to expedition-level technical diving.
Book Your Tec Trimix 65 Course
Spaces are limited to ensure maximum safety and personalised coaching.
Contact Professional Diver Training or reach out via Go2Similan Diving for availability, prerequisites and gas-cost estimates.