Unit of competency details

SISOSCB317A - Complete a dive using Enriched Air Nitrox (Release 1)


Usage recommendation:
Is superseded by SISOSCB008 - SCUBA dive using Enriched Air NitroxNot equivalent. Significant changes to performance criteria and knowledge evidence. 10/Sep/2019
Supersedes and is equivalent to SROSCB025A - Complete a dive using Enriched Air Nitrox (EANx)E Updated and equivalent to SROSCB025A Complete a dive using Enriched Air Nitrox (EANx) 06/Jun/2011

Release Status:
ReleaseRelease date
(View details for release 2) 28/Nov/2011
1 (this release) 07/Jun/2011

Replaced release

You are currently viewing the components related to release 1.
The current release is release 2View release 2 details.

Accredited courses that have this unit in the completion mapping

Training packages that include this unit


SchemeCodeClassification value
ASCED Module/Unit of Competency Field of Education Identifier 092101 Sport And Recreation Activities  

Classification history

SchemeCodeClassification valueStart dateEnd date
ASCED Module/Unit of Competency Field of Education Identifier 092101 Sport And Recreation Activities  18/Nov/2011 
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Modification History

Not Applicable

Unit Descriptor

Unit descriptor 

This unit describes the performance outcomes, skills and knowledge required to plan and perform an EANx dive under supervision. This unit also focuses on disassembling and maintaining equipment used for EANx dives.

No licensing, regulatory or certification requirements apply to this unit at the time of endorsement.

Application of the Unit

Application of the unit 

This unit applies to current or aspiring specialty SCUBA dive guides or instructors responsible for planning and performing controlled open water dives under supervision using enriched air nitrox (EANx). This may include those working for private dive schools or companies operating at coastal sites or through holiday resorts.

This may also include those working for, volunteer organisations, not for profit organisations, government agencies, or group instructors in outdoor education programs.

Licensing/Regulatory Information

Refer to Unit Descriptor


Prerequisite units 

  • SISOSCB301A SCUBA dive in open water to a maximum depth of 18 metres

Employability Skills Information

Employability skills 

This unit contains employability skills.

Elements and Performance Criteria Pre-Content

Elements describe the essential outcomes of a unit of competency.

Performance criteria describe the performance needed to demonstrate achievement of the element. Where bold italicised text is used, further information is detailed in the required skills and knowledge section and the range statement. Assessment of performance is to be consistent with the evidence guide.

Elements and Performance Criteria



1. Plan an EANx dive.

1.1. Identify the requirements  of EANx use and associated hazards .

1.2. Prepare EANx dive plan  according to industry technical and safety criteria , relevant legislation  and organisational policies and procedures .

1.3. Select a suitable dive site according to industry technical and safety criteria, relevant legislation and organisational policies and procedures.

2. Select equipment.

2.1. Select blend and equipment  according to industry technical and safety criteria.

2.2. Perform pre dive checks  and maintenance  of EANx equipment according to industry technical and safety criteria, manufacturer's recommendations and organisational policies and procedures.

3. Dive using EANx.

3.1. Complete EANx dive according to dive plan, EANx criteria and industry technical and safety criteria.

3.2. Monitor depth and time throughout dive.

3.3. Take remedial action to avoid hazards.

4. Disassemble and maintain equipment.

4.1. Maintain positive pressure in the cylinder to avoid entry of atmospheric air.

4.2. Disassemble regulators and gauges according to industry technical and safety criteria.

4.3. Undertake service and maintenance of equipment with parts compatible with elevated oxygen mix according to industry technical and safety criteria.

5. Evaluate EANx dive.

5.1. Evaluate relevant aspects  of the EANx dive.

5.2. Identify improvements for future EANx dives.

Required Skills and Knowledge


This section describes the skills and knowledge required for this unit.

Required skills 

  • planning and organising skills to:
  • devise a suitable EANx dive plan
  • check, maintain and disassemble equipment
  • self management and observation skills to:
  • perform pre dive checks and maintenance of EANx equipment
  • monitor depth and time throughout dive
  • problem-solving skills to:
  • anticipate and eliminate potential hazards associated with EANx diving
  • calculate gas mixtures
  • develop and make decisions regarding gas plan
  • numeracy skills to calculate safe blends and percentages of oxygen and nitrogen
  • first aid and emergency response skills appropriate to the site to enable initial response to EANx emergencies and personal health care.

Required knowledge 

  • legislation, organisational policies and procedures, industry standards and industry technical and safety criteria to enable safe conduct of EANx diving activities
  • equipment types, characteristics and technology used for EANx diving, the advantages and disadvantages of the range of equipment and factors affecting appropriate selection
  • principles of mixing gas, the different types of gas and its application in EANx diving
  • requirements and hazards associated with EANx diving and how to negotiate these
  • no decompression limits for EANx diving
  • emergency, first aid and rescue procedures appropriate to the location to ensure risk minimisation to self and group.

Evidence Guide


The evidence guide provides advice on assessment and must be read in conjunction with the performance criteria, required skills and knowledge, range statement and the Assessment Guidelines for the Training Package.

Overview of assessment 

Critical aspects for assessment and evidence required to demonstrate competency in this unit 

Evidence of the following is essential:

  • applies relevant process to plan for EANx diving, complete safely checks and maintain and disassemble EANx equipment
  • calculates gas mixtures and no decompression limits according to industry technical and safety criteria, relevant legislation and organisational policies and procedures
  • determines and negotiates specific EANx requirements, hazards and factors affecting diving with EANx
  • evaluates and reflects on own EANx diving performance to identify strengths, weaknesses and areas that need improvement.

Context of and specific resources for assessment 

Assessment must ensure participation in multiple EANx diving activities to demonstrate competency and consistency of performance.

Assessment must also ensure access to:

  • resources and information to plan and select appropriate equipment for EANx diving
  • an open water site suitable for EANx diving
  • a suitable diving boat, if required
  • SCUBA equipment and specific EANx diving equipment.

Method of assessment 

A range of assessment methods should be used to assess practical skills and knowledge. The following examples are appropriate for this unit:

  • oral or written questioning to assess knowledge of EANx requirements, gas mixtures, and hazards associated with diving using EANx
  • observation of safe participation and handling of EANx equipment throughout diving process
  • third-party reports from a supervisor detailing performance.

Holistic assessment with other units relevant to the industry sector, workplace and job role is recommended.

Guidance information for assessment 

Range Statement


The range statement relates to the unit of competency as a whole. It allows for different work environments and situations that may affect performance. Bold italicised wording, if used in the performance criteria, is detailed below. Essential operating conditions that may be present with training and assessment (depending on the work situation, needs of the candidate, accessibility of the item, and local industry and regional contexts) may also be included.

Requirements  may include:

  • approved cylinders
  • colour coding
  • dive planning
  • stamping
  • compliance
  • adequate filtering
  • compatible equipment and materials.

Hazards  may include:

  • hypothermia
  • group management hazards
  • equipment contamination
  • oxygen toxicity
  • explosion risk
  • decompression illness
  • EANx blend analysis.

EANx dive plan  may include:

  • objectives
  • date, time and duration of dive
  • site, equipment and resources
  • safety and emergency procedures
  • experience and or expertise of dive team
  • buoyancy
  • dive log
  • no-decompression limits
  • gas plan
  • calculation of partial oxygen to determine oxygen
  • risk management plan.

Industry technical and safety criteria  may include:

  • British Sub-Aqua Club (BSAC)
  • Professional Association of Diving Instructors (PADI)
  • SCUBA Schools International (SSI).

Relevant legislation  may include:

  • occupational health and safety
  • permits or permission for access
  • environmental regulations
  • marine regulations.

Organisational policies and procedures  may include:

  • occupational health and safety
  • communication protocols
  • EANx dive and gas plans
  • code of ethics
  • manufacturer's recommendations
  • minimal impact codes
  • EANx criteria.

Blend and equipment  may include:

  • cylinder
  • regulator
  • gauges and accessories
  • valves
  • oxygen compatibility or clean
  • labelling
  • blend analysis.

Pre dive checks  may include:

  • dive and gas plans
  • the maximum depth for the breathing gas and loss of breathing gas procedures
  • buddy separation procedures.

Maintenance  may include:

  • cylinder specifications
  • coding
  • stamping
  • safety log
  • oxygen cleaning of equipment.

Relevant aspects  may include:

  • objectives
  • planning process
  • activity site
  • weather
  • equipment selection
  • clothing selection
  • food selection
  • instructional content
  • instructional technique
  • assessment technique
  • group feedback
  • directing techniques
  • rescue techniques employed.

Unit Sector(s)

Unit sector 

Outdoor Recreation

Co-requisite units

Co-requisite units 

Competency field

Competency field