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Diving Equipment and Plymouth Diving

The hardest Trimix course on the planet

GUE Tech Courses

Duration: 6 days

Tec 1 has set the industry benchmark for normoxic trimix training. It is simply the most complete and thorough training course available for divers that wish to explore the amazing dive sites that lie outside of the realm of recreational diving. By using GUE’s team based approach to dive planning, decompression and conservative gas choices, safety and enjoyment are maximised.

Technical diver level 1 is the right course for you if you if you have technical pass at Fundamentals want to achieve a deeper understanding of:

  • The use of a twinset and in the potential failure problems associated with them: By building on the skills learned in Fundamentals you will learn to identify and resolve various failure modes of manifolds and regulators increasing your safety.
  • The use of Nitrox for accelerated and general decompression strategies: Get more bottom time as your dives can be safely extended beyond recreational no stop limits using either 50% or 100% oxygen for decompression efficiency and safety.
  • The use of normoxic Helium gas mixes to minimize narcosis to maximum depth of 51m: GUE standard gasses reduce the narcosis problems associated with increased gas density and open up a world of new dive locations giving the maximum safety and enjoyment.
  • The applications of single decompression stage diving, with respect to decompression procedures: Start to build a solid foundation of experience with a single stage bottle and planning a maximum of 30 minutes of adjusted decompression laying the foundations for Technical diver level 2.


What will you learn on this course?
Tec 1 is uniquely designed around the needs of the diver to further cultivate the three essential foundations of sound technical diving practice, capacity, awareness and efficiency.

Tec 1 teaches the diver the highest standard of safety, dive planning, teamwork and problem resolution when a mandatory decompression obligation is anticipated or in place. As with all other GUE training this is achieved through developing individual capacity and high quality team skills.

We do this over 6 days with at least ten hours of academics and nine dives, six of which will be critical-skill dives and three will be experience dives utilizing Trimix. Initial dives will be conducted in shallow water to test diver ability and to fill in any deficits in skill levels. The last three dives are to be Trimix dives at depth for experience. There is also a swim test of 375m in under 14 minutes and breath hold swim of 18m.

In summary the course can be broken in to four essential components.

Academic topics: We will develop your working knowledge of nitrox, normoxic and hyperoxic Trimix and decompression mixtures, including history, physics, physiology, tables, and operational considerations. Plus gas planning, dive planning and in depth understanding of equipment and failures.

Land Drills: Before entering the water you will have had the opportunity to rehearse critical skills such as reel and guideline use, dive team order and protocols, touch contact, manifold operation and failures. Plus the use of safety spools, reels and basic navigation skills and pre-dive drills.

Training dives: In addition to further refining the skills learned in Fundamentals you will also learn many new skills in shallow water including:

  • Procedures for gas failures, including valve manipulation, gas-sharing, and regulator switching as appropriate.
  • The use of touch contact for limited and simulated zero-visibility situations.
  • Reel and guideline use.
  • Gas-sharing scenarios, to include a prolonged gas-sharing event.
  • The effective deployment of a reserve light
  • Reasonable proficiency with a single decompression cylinder.
  • Proficiency with effective decompression techniques, including depth and time management.
  • A comfortable demeanour while sharing gas without a mask.
  • Dive-rescue techniques, including effective management of unconscious diver. Including differences between the management of unconscious and toxing diver. 


Experience dives: Before the end of your course you will also conduct three full trimix decompression dives to maximum of 51m with your instructor to allow you to gain essential experience with a watchful eye!