North Florida Cave and Technical Diving

Advanced Trimix Diver Course

Advanced Trimix

This course provides the training required to competently and safely utilize breathing gases containing helium for dives that require staged decompression to a maximum depth of 330 fsw while utilizing nitrox mixtures and oxygen during decompression. The objective of this course is to train divers in the benefits, hazards and proper procedures for utilizing custom Trimix mixtures as breathing gas.

  • Each diver must provide double tank bottom mix cylinders with a minimum capacity of 142 cubic feet, two decompression gas cylinders with a minimum volume of 40Ýcubic feet and an oxygen-clean decompression mix cylinder with a minimum volume of 40 cubic feet. Multiple double tanks and travel mix cylinders are helpful, but not required. A trimix computer and bottom timer/depth gauge are required along with slates sufficient for noting the total dive schedule. Your instructor will provide the use of a Trimix analyzer. A laptop computer is highly recommended, but not required.
  • The Advanced Trimix Diver Course requires four days and a minimum of four dives for completion. Heavy emphasis is placed on dive planning using appropriate gas mixtures and volumes for the planned dives and accurate dive execution according to the dive plan established. Curriculum is as follows:

Day One Class session, gear configuration, open water drills and a limited penetration dive into Devil’s Cave System to practice oxygen and decompression cylinder pickups and drop-offs.

Day Two Completion of academics and dive planning and execution of two trimix dives to the 180- to 220-foot range. Unless the diver has previously completed my Extended Range, Technical Diver or Normoxic Trimix course, these dives will occur in an open water setting at Hal Watts Forty Fathom Grotto. In the event such previous training has occurred, alternate sites may be utilized — Peacock III/Henley’s Castle, Lower Orange Grove, etc.

Day Three Dive planning and execution at Eagle’s Nest or Diepolder II or III.

Day Four Dive planning and execution at Eagle’s Nest or Diepolder II or III.


Prerequisites: A minimum of 18 years of age, certification as TDI Extended Range Diver or TDI Entry Level Trimix Diver (or equivalent) and a minimum of 100 logged dives.

Certification Available: TDI.

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North Florida Cave
and Technical Divers

PO Box 489 • Branford
Florida 32008-0489

(352) 404-5501

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