BSAC Sports Mixed Gas Diver

sports mixed gas diver front 21 001 300x189 BSAC Sports Mixed Gas Diver

Course aims

The course aims are to teach Sports Divers in the use of Mixed Gas to a depth of 35 metres. For Dive Leaders and above, providing that they have the practical depth experience, then the maximum depth can be extended up to 50 metres.  Dives are conducted using a breathing gas mixture of oxygen percentage greater than or equal to 20 % and a helium percentage of up to 30 %, for example, 20/30. This mixture contains the maximum permitted percentage of helium gas component for a Sports Mixed Gas Diver, within the prescribed practical tolerances based on the final mixed gas percentages.

Big Blue Package – 15,000 THB
- Air Conditioned Accommodation
- Boat Fees
- Equipment Rental
- Gas fills and Cylinder Fees + Helium

- Study Crew Pack with reference CD-Rom
- Big Blue BSAC Club T-Shirt and Mask Strap
- Certification

Entry requirement

The entry requirements for the BSAC Sports Mixed Gas Diver are:

  • Be a minimum of 18 years of age
  • Hold a minimum diver grade of BSAC Sports Diver (or equivalent with a valid 35 metre depth certification)
  • Provide logged evidence demonstrating a minimum of 10 dives under different conditions in the range 30 to 35 metres
  • Have 60 – logged dives
  • Be a BSAC Advanced Nitrox Diver or BSAC Accelerated Decompression Procedures Diver (or equivalent)
  • Be a BSAC Extended Range Diver who can demonstrate a minimum of 10 logged extended range dives within the last 2 years, using appropriate equipment, to depths in the region of 40 metres.

Course duration

The duration of this course is 2 days

Course contents

The Sports Mixed Gas diver course consists of the following elements:

  • Six classroom lessons
  • A theory assessment
  • A dry practical lesson of 90 minutes
    • One or more confined water lessons of not less than 90 minutes total in-water duration
    • Two open water lessons, dependant on student performance, with a total underwater duration of not less than 120 minutes and an individual lesson duration of not less than 45 minutes.

All practical training conducted in both confined and open water includes the achievement of specific performance standards at appropriate points throughout the lessons.

Theory Lessons

Lesson 1 Starts with an overview and objectives of the course. Following this course introduction, we will take a look at the benefits of using Mixed Gas as well as some considerations and implications of using these gases.  Rescuing an unconscious diver from depth when mandatory decompression stops are necessary creates some issues, so in this lesson we look at how to deal with this situation.

To train, as a Mixed Gas Diver is not just about completing the theory lessons and assessment skills and dives, but it is about having the correct approach and right attitude toward this type of diving. Gaining experience progressively as well as being a responsible diver is a big part of this course and we now look at these issues in turn.

Lesson -2 Starts off with looking at some of the safe diving practices relating to Mix Gas Diving, issues such as, maximum depths, pp O2 levels, minimum and maximum mixes, oxygen decompression and guidance on using decompression tools. The next step is to look at the history of mixed gas use and the different types of mixed gases. We look at how Helium reduces the Oxygen Toxicity and Narcosis levels within mixed gas as well as looking at the different ratio of gas mixtures.  This lesson will also cover some of the benefits of using Helium. For example, better regulator and breathing performance, which is very important when diving at depth, is just one of these benefits. Other topics in this lesson covers, gas analyzing, the costs of purchasing Helium, decompression using Trimix, the need for gas switching etc.

Mixed Gas diving means that you will require additional equipment: This equipment consist of the following, Primary equipment, secondary equipment and redundancy equipment. The third lesson lists each type of equipment in each of the above-mentioned sections.

With all this additional equipment, the next step to consider is the configuration of this equipment in order that you can access it and use it; second nature. Trimix diving usually means that almost certainly decompression requirements will be needed. Decompression stops can range from a few minutes to hours. To comfortably carry out prolong decompression stops, we need to use decompression stations.

These decompression stations either uses simple Shot line configuration or more complicated one such as, a multiple trapeze. If for some reason, you cannot return to these stations then a Delayed Surface Marker Buoy or the use of a Lift Bag as deployment back up will need to be deployed. The use of these two systems will be also covered in this lesson.

Physiology! Most divers will remember this topic from their elementary diving course. Some divers find this topic interesting, some divers still find it difficult to understand. In this course it is crucial that you fully understand this subject in depth. Apart from the standard diving and Nitrox related physiology, using Helium has some additional physiology issues. Therefore the four sections of these theory lessons will review standard diving physiology, and introduces you to physiology concerns relating to breathing Helium.

Section 5 addresses Dive Planning for Mixed Gas divers. In this lesson we look at, using PC Decompression software that is typically used for Technical Diving.

Both the diver’s physical and mental preparation for a deep dive is important. Being fully prepared in order to complete the dive effectively and safely. In this lesson we show you how to effectively visualize your plan showing you how to complete each step of the dive in the right order. Next on the list is to run you through your gas calculations, which will include, your bottom gas, decompression stops gas and reserve gas requirements. For gas monitoring we will use the standard ‘’rule of thirds” and “rules of halves” for deco phase. The usual Oxygen CNS and UPTD’s tracking will also be reviewed in this lesson. The lesson finishes with several practical planning sessions.

As a Mixed Gas diver, you may be called upon to act as surface support or act as the Dive Manager for a group. This means that you will be in charge of the safety and overall conduct of these divers. This will mean that you are not only aware of every ones dive plan but will also know what to do if an emergency occurs.  It will be your ultimate responsibility for monitoring all sections of the dive. Lesson 6 is aimed at the roles, responsibility and activities of a Dive Manger.

Theory Assessment

This exam is an open book exam, which consists of 36 questions. Questions are in both multi choice and short written answers formats. Successful candidates will need to achieve a minimum of 80% pass mark

Practical Dry Lesson

This is used as a configuration workshop. As an Extended Range Diver you will already have some idea of your own personal equipment configuration so this may mean that there will be some tweaking here and there when introducing the Helium related equipment.

Practical Skills

The skills lesson is conducted in a confined water environment in which the depth will not exceed 10 metres maximum depth.

The following skills to master in this section are:

Dive briefings, accurate gas analyzing, show your ability to use both twin set cylinder configuration and stage cylinder skills, proper weighting and trim, gas switching achieving natural buoyancy at one metre increments on the ascent, mask exchange, isolator shutdown procedures, dealing with hose/regulator failure, remove and refit stage cylinders, breathing from buddy’s second regulator, Deployment of a DSMB and conduct your decompression stops within 0.5 +/- of a metre. These skill are just a few to mention.

Open Water Dives

Both open water dives will start with a meticulous dive plan being performed. Dive profiling, gas requirements, gas analyzing, emergency back up plans etc should all be incorporated within this plan.

Dive 1

The maximum depth of dive 1, should not exceed 50 metres. On this dive you will perform the following skills,

Descend and conduct a bubble check. On reaching the seabed you will then demonstration effective buoyancy and trim. You will then conduct cylinder isolation procedure followed by gas switching skills.

On the dive phase you will be expected to establish effective gas monitoring and run time management. At the end of the dive you will conduct a mid-water deployment of a DSMB. On reaching your deco stop, you will then run through an exercise where you will hand off your stage gas to your buddy. At this stage you will also carry out your decompression stops as required.

Dive 2

On this dive you will plan a dive with an ascent/decompression time between 30 -45 minutes. Again the maximum depth should not exceed 50 metres. The procedure for this dive is identical to dive 1with the exception of the hand off stage cylinder skill.

On surfacing from both of these dives the diver will follow some post dive actions, such as breathing a rich gas for a period of time and drinking fluids, plus equipment shutdown procedures.

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