SIST EN ISO 24807:2024
(Main)Recreational diving services - Requirements for rebreather diver training - Decompression diving to 100 m (ISO 24807:2023)
Recreational diving services - Requirements for rebreather diver training - Decompression diving to 100 m (ISO 24807:2023)
This document specifies requirements for rebreather diver training programmes which provide the competencies required to perform dives to 100 m with a rebreather requiring mandatory decompression stops using a breathing mixture containing helium. This document specifies evaluation criteria for these competencies.
This document specifies the requirements under which training is provided, in addition to the general requirements for recreational diving service provision in accordance with ISO 24803.
Dienstleistungen des Freizeittauchens - Anforderungen an die Ausbildung von Kreislaufgerätetauchenden - Dekompressionstauchen bis 100 m (ISO 24807:2023)
Dieses Dokument legt Anforderungen für Ausbildungsprogramme für Kreislaufgerätetauchende fest, die die erforderlichen Kompetenzen vermitteln, um Tauchgänge bis 100 m mit einem Kreislaufgerät unter Verwendung eines heliumhaltigen Atemgasgemisches durchzuführen, die obligatorische Dekompressionsstopps erfordern.
Dieses Dokument legt Bewertungskriterien für diese Kompetenzen fest.
Dieses Dokument legt die Anforderungen fest, unter denen die Ausbildung zusätzlich zu den allgemeinen Anforderungen für die Erbringung von Dienstleistungen im Bereich des Freizeittauchens nach ISO 24803 durchgeführt wird.
Services relatifs à la plongée de loisirs - Exigences concernant la formation des plongeurs à l’utilisation des recycleurs - Plongée avec décompression jusqu’à 100 m (ISO 24807:2023)
Storitve rekreativnega potapljanja - Zahteve za usposabljanje rekreativnih potapljačev - Dekompresijsko potapljanje do 100 m (ISO 24807:2023)
Ta dokument določa zahteve za programe usposabljanja rekreativnih potapljačev. Zahteve določajo usposobljenost za izvajanje potopov do 100 m globine z dihalnim krogom z obveznimi dekompresijskimi postanki z dihalno mešanico, ki vsebuje helij. Dokument določa merila za ocenjevanje te usposobljenosti.
Prav tako določa pogoje, pod katerimi je izvedeno usposabljanje, poleg splošnih zahtev za izvajanje aktivnosti centrov za rekreativno potapljanje v skladu s standardom ISO 24803.
General Information
Standards Content (Sample)
SLOVENSKI STANDARD
01-junij-2024
Storitve rekreativnega potapljanja - Zahteve za usposabljanje rekreativnih
potapljačev - Dekompresijsko potapljanje do 100 m (ISO 24807:2023)
Recreational diving services - Requirements for rebreather diver training -
Decompression diving to 100 m (ISO 24807:2023)
Dienstleistungen des Freizeittauchens - Anforderungen an die Ausbildung von
Kreislaufgerätetauchenden - Dekompressionstauchen bis 100 m (ISO 24807:2023)
Services relatifs à la plongée de loisirs - Exigences concernant la formation des
plongeurs à l’utilisation des recycleurs - Plongée avec décompression jusqu’à 100 m
(ISO 24807:2023)
Ta slovenski standard je istoveten z: EN ISO 24807:2024
ICS:
03.080.99 Druge storitve Other services
03.200.99 Drugi standardi v zvezi s Other standards relating to
prostim časom in turizmom leisure and tourism
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
EN ISO 24807
EUROPEAN STANDARD
NORME EUROPÉENNE
March 2024
EUROPÄISCHE NORM
ICS 03.080.30; 03.100.30; 03.200.99
English Version
Recreational diving services - Requirements for rebreather
diver training - Decompression diving to 100 m (ISO
24807:2023)
Services relatifs à la plongée de loisirs - Exigences Dienstleistungen des Freizeittauchens - Anforderungen
concernant la formation des plongeurs à l'utilisation an die Ausbildung von Kreislaufgerätetauchenden -
des recycleurs - Plongée avec décompression jusqu'à Dekompressionstauchen bis 100 m (ISO 24807:2023)
100 m (ISO 24807:2023)
This European Standard was approved by CEN on 11 September 2023.
CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this
European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references
concerning such national standards may be obtained on application to the CEN-CENELEC Management Centre or to any CEN
member.
This European Standard exists in three official versions (English, French, German). A version in any other language made by
translation under the responsibility of a CEN member into its own language and notified to the CEN-CENELEC Management
Centre has the same status as the official versions.
CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia,
Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway,
Poland, Portugal, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Türkiye and
United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION
EUROPÄISCHES KOMITEE FÜR NORMUNG
CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2024 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 24807:2024 E
worldwide for CEN national Members.
Contents Page
European foreword . 3
Annex C (informative) A–deviations. 4
European foreword
This document (EN ISO 24807:2024 has been prepared by Technical Committee ISO/TC 228 "Tourism
and related services" in collaboration with Technical Committee CEN/TC 329 “Tourism services” the
secretariat of which is held by DIN.
This European Standard shall be given the status of a national standard, either by publication of an
identical text or by endorsement, at the latest by September 2024, and conflicting national standards
shall be withdrawn at the latest by September 2024.
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CEN shall not be held responsible for identifying any or all such patent rights.
Any feedback and questions on this document should be directed to the users’ national standards
body/national committee. A complete listing of these bodies can be found on the CEN website.
According to the CEN-CENELEC Internal Regulations, the national standards organizations of the
following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria,
Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland,
Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Republic of
North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Türkiye and the
United Kingdom.
Endorsement notice
The text of ISO 24807:2023 has been approved by CEN as EN ISO 24807:2024without any modification.
Annex C
(informative)
A–deviations
A- deviation: National deviation due to regulations, the alteration of which is for the time being outside
the competence of the CEN/ CENELEC member.
This European standard does not fall under any Directive of the EU.
In the relevant CEN-CENELEC countries, these A-deviations are valid instead of the provisions of the
European standard, until they have been removed.
Clause Deviation
Scope French deviation
National regulation: "Code du Sport, Livre III : Pratique sportive, Titre II:
Obligations liées aux activités sportives, Section 3: Établissements qui organisent
la pratique ou dispensent l’enseignement de la plongée subaquatique"
The scope of this standard is not compatible with the national regulation
mentioned above and its subsequent annexes related to rebreather diver training
programmes, competencies and specifies evaluation criteria for these
competencies.
Therefore, the whole standard is note applicable in France and the document is
not adopted as a national standard.
Normative French deviation
reference
In clause 2 “Normative references” the following documents, in whole or in part,
are normatively referenced in prEN ISO 24807 and are indispensable for its
application:
ISO 24801-3, Recreational diving services — Requirements for the training of
recreational scuba divers — Part 3: Level 3
ISO 24802-2, Recreational diving services — Requirements for the training of
scuba instructors — Part 2: Level 2
ISO 24803, Recreational diving services — Requirements for recreational diving
providers
ISO 24806, Recreational diving services — Requirements for rebreather diving
training —decompression diving to 60 meters
All references above were not adopted and are not applicable in their entirety in
France.
INTERNATIONAL ISO
STANDARD 24807
First edition
2023-10
Recreational diving services —
Requirements for rebreather diver
training — Decompression diving to
100 m
Services relatifs à la plongée de loisirs — Exigences concernant la
formation des plongeurs à l’utilisation des recycleurs — Plongée avec
décompression jusqu’à 100 m
Reference number
ISO 24807:2023(E)
ISO 24807:2023(E)
© ISO 2023
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting on
the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address below
or ISO’s member body in the country of the requester.
ISO copyright office
CP 401 • Ch. de Blandonnet 8
CH-1214 Vernier, Geneva
Phone: +41 22 749 01 11
Email: copyright@iso.org
Website: www.iso.org
Published in Switzerland
ii
ISO 24807:2023(E)
Contents Page
Foreword .v
Introduction . vi
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Competencies . 3
5 Prerequisites for training . 4
5.1 General . 4
5.2 Minimum age . 4
5.3 Diving experience . 4
5.4 Health requirements . 4
6 Introductory information . 5
7 Theoretical knowledge . 5
7.1 Knowledge review . 5
7.2 Risk management . 5
7.3 Team diving . 6
7.4 Project dives with specific objectives . 7
7.5 Function of rebreather components . 7
7.6 Breathing performance using a rebreather . 8
7.7 Rebreather assembly and checks . 8
7.8 Gas supply duration . 9
7.9 CO absorbent duration . 9
7.10 Rebreather pre-water entry checks . 9
7.11 Advanced decompression dive planning . 10
7.12 Dive conduct . 10
7.13 Identifying and reacting to potential issues . 11
7.14 Hypercapnia, hypoxia and hyperoxia .12
7.15 Buddy and team diving procedures .12
7.16 Rebreather maintenance .13
7.17 Maintaining knowledge and skills . 13
8 Practical skills .13
8.1 Skills review .13
8.2 General .13
8.3 Pre-dive procedures . 14
8.4 Dive conduct . 14
8.5 Emergency situations .15
8.6 Response to rebreather malfunctions . 15
8.7 Post-dive procedures . 16
9 Instructors .16
10 Training equipment and materials .16
10.1 Training equipment . 16
10.2 Training materials . 17
11 Practical training parameters .17
11.1 Training dives or in-water sessions . 17
11.2 Instructor responsibilities . 18
11.2.1 General . 18
11.2.2 Instructor-to-student ratios for dives of 60 m or less . 18
11.2.3 Instructor-to-student ratios for dives deeper than 60 m . 18
11.3 Rebreather dive leaders . 18
11.4 Breathing gas limits . 18
iii
ISO 24807:2023(E)
11.4.1 Closed-circuit rebreather . 18
11.4.2 Semi-closed rebreather . 19
12 E v a luat ion .19
12.1 Knowledge . 19
12.2 Skill evaluation . 19
12.3 Proof of qualification . 19
Annex A (informative) Gas density and gas mixtures .21
Annex B (normative) Student crossover training programmes.23
Bibliography .24
iv
ISO 24807:2023(E)
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards
bodies (ISO member bodies). The work of preparing International Standards is normally carried out
through ISO technical committees. Each member body interested in a subject for which a technical
committee has been established has the right to be represented on that committee. International
organizations, governmental and non-governmental, in liaison with ISO, also take part in the work.
ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of
electrotechnical standardization.
The procedures used to develop this document and those intended for its further maintenance are
described in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the
different types of ISO document should be noted. This document was drafted in accordance with the
editorial rules of the ISO/IEC Directives, Part 2 (see www.iso.org/directives).
ISO draws attention to the possibility that the implementation of this document may involve the use
of (a) patent(s). ISO takes no position concerning the evidence, validity or applicability of any claimed
patent rights in respect thereof. As of the date of publication of this document, ISO had not received
notice of (a) patent(s) which may be required to implement this document. However, implementers are
cautioned that this may not represent the latest information, which may be obtained from the patent
database available at www.iso.org/patents. ISO shall not be held responsible for identifying any or all
such patent rights.
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation of the voluntary nature of standards, the meaning of ISO specific terms and
expressions related to conformity assessment, as well as information about ISO's adherence to
the World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT), see
www.iso.org/iso/foreword.html.
This document was prepared by Technical Committee ISO/TC 228, Tourism and related services, in
collaboration with the European Committee for Standardization (CEN) Technical Committee CEN/
TC 329, Tourism services, in accordance with the Agreement on technical cooperation between ISO and
CEN (Vienna Agreement).
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www.iso.org/members.html.
v
ISO 24807:2023(E)
Introduction
Rebreathers (i.e. breathing devices that recirculate some or all of the diver’s exhaled breath and
replenish any consumed oxygen to maintain a breathable mixture) are becoming much more widely
available and popular among divers. The market for rebreather diving has been constantly growing
in recent years and is now considered to be large enough that the need for standards for training
organizations on minimum training requirements is evident. Rebreathers allow divers to dive for
longer and to greater depths. Such depths can go beyond 30 m and can therefore require mandatory
decompression stops. If rebreathers are used improperly, they can be hazardous; divers have had fatal
accidents due to incorrect use of these devices. It is therefore important to specify training for diving
with such devices.
Training organizations offering training that conforms with this document may exceed any of the
requirements in terms of the volume or complexity of training but should at least ensure the students
master all the skills and knowledge defined in this document.
vi
INTERNATIONAL STANDARD ISO 24807:2023(E)
Recreational diving services — Requirements for
rebreather diver training — Decompression diving to
100 m
1 Scope
This document specifies requirements for rebreather diver training programmes which provide
the competencies required to perform dives to 100 m with a rebreather using a breathing mixture
containing helium and requiring mandatory decompression stops.
This document specifies evaluation criteria for these competencies.
This document specifies the requirements under which training is provided, in addition to the general
requirements for recreational diving service provision in accordance with ISO 24803.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements of this document. For dated references, only the edition cited applies. For
undated references, the latest edition of the referenced document (including any amendments) applies.
ISO 24801-3, Recreational diving services — Requirements for the training of recreational scuba divers —
Part 3: Level 3 — Dive leader
ISO 24802-2, Recreational diving services — Requirements for the training of scuba instructors — Part 2:
Level 2
ISO 24803, Recreational diving services — Requirements for recreational diving providers
ISO 24806, Recreational diving services — Requirements for rebreather diver training — Decompression
diving to 60 m
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
ISO and IEC maintain terminology databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https:// www. iso. org/o bp
— IEC Electropedia: available at https:// www.e lectropedia. org/
3.1
rebreather
apparatus that has a supply of gas carried by the diver, allowing the diver to breathe under water
which enables the diver to inspire gas from a facepiece connected to a counterlung and to pass exhaled
gas through a carbon dioxide absorption material before it is re-breathed from the counterlung and
inspired partial pressure of the gases within the apparatus remain within acceptable physiological
limits so that gas is thus recirculated within the apparatus
Note 1 to entry: A rebreather can also be called a self-contained rebreathing apparatus.
Note 2 to entry: A facepiece can be a mouthpiece assembly, a half mask, a full-face mask or a helmet.
ISO 24807:2023(E)
[SOURCE: EN 14143:2013, 3.1, modified — Note 1 to entry modified and Note 2 to entry added. This
content has been reproduced with the permission of CEN. Copyright remains with CEN.]
3.2
rebreather type
primary rebreather design
EXAMPLE Closed-circuit rebreather (CCR), manually controlled closed-circuit rebreather (mCCR),
electronically controlled closed-circuit rebreather (eCCR), semiclosed-circuit rebreather (SCR), manually
controlled SCR (mSCR), electronically controlled SCR (eSCR), hybrid closed-circuit rebreather (hCCR).
3.3
rebreather unit
type of rebreather (3.1) having consistent controls, displays and configuration over several rebreather
models (3.4), where the operation is essentially the same from rebreather model to rebreather model
3.4
rebreather model
specific individual design of rebreather (3.1) made by a manufacturer
3.5
breathing gas
gas present in the breathing loop (3.11) inspired by the diver
3.6
supply gas
gas present in a cylinder which can be added to the breathing loop (3.11)
3.7
bailout gas
gas present in a cylinder that can be breathed directly by the diver
3.8
PO
partial pressure of oxygen in a gas mixture
Note 1 to entry: This usually refers specifically to the breathing-gas mixture inhaled by a diver.
3.9
set-point
PO set-point
PO value that is used by a control system to determine when a solenoid valve injects oxygen into the
breathing loop (3.11)
3.10
respiratory minute volume
RMV
product of the tidal volume and breathing frequency measured in litres per minute
[SOURCE: EN 14143:2013, 3.10]
3.11
breathing loop
portion of a rebreather (3.1) through which gas circulates, usually consisting of a mouthpiece, breathing
hose(s), counterlung(s), non-return valves and a CO absorbent canister
3.12
scrubber
canister in the breathing loop (3.11) containing CO absorbent
ISO 24807:2023(E)
3.13
confined water
swimming pool with a depth appropriate to the activity or body of water, offering similar conditions
with regard to visibility, depth, water movement and access
[SOURCE: ISO 24801-2:2014, 3.5]
3.14
open water
body of water significantly larger than a swimming pool, offering conditions typical of a natural body
of water
[SOURCE: ISO 24801-2:2014, 3.6]
3.15
limited open water
open water (3.14) no deeper than 20 metres with no appreciable water movement and visibility that is
sufficient to allow effective student supervision and skill development
3.16
service provider
entity (individual or organization), including any individual acting on behalf of such an entity, which
offers one or more of the following services:
— introductory diving activities;
— snorkelling excursions;
— provision of training and education;
— organized and guided diving for qualified divers;
— rental of diving equipment.
[SOURCE: ISO 24803:2017, 3.1]
3.17
safety stop
non-mandatory decompression stop (3.18) near the surface prior to surfacing
3.18
decompression stop
mandatory stop during ascent from depth prior to surfacing
3.19
decompression diving
diving with mandatory decompression stops (3.18)
3.20
delayed surface marker buoy
DSMB
surface marker buoy that can be deployed by a diver from underwater
4 Competencies
The training programme shall ensure that students are qualified to independently plan and conduct
dives requiring mandatory decompression stops using the specific rebreather unit for which the diver
has received training.
ISO 24807:2023(E)
Divers qualified in accordance with this document are competent to dive with a suitably qualified
buddy to 100 m using a rebreather with a supply gas containing:
— a minimum of 5 % oxygen;
— sufficient helium to control narcosis and to ensure a breathing gas density of less than 6,3 g/l.
In order to be deemed qualified to dive with a specific rebreather unit other than the one that the diver
has received training for, a diver will need further unit-specific training.
The training programme shall ensure that the student has a full understanding of any theoretical
concepts or skills applicable to the rebreather type, rebreather unit and rebreather model they will
use. Students shall be provided with an overview of any information that is not specific to their
rebreather, but this only needs to be informative in nature so that they are aware of the general possible
configurations that other divers could use.
Student crossover training programmes shall be carried out in accordance with Annex B.
NOTE Following qualification in accordance with this document, a diver can incrementally build experience
and competence to eventually be capable of diving to depths beyond 100 m using proper risk management
protocols.
5 Prerequisites for training
5.1 General
The service provider shall ensure that the student fulfils the following prerequisites to take part in the
training course envisaged.
In order to participate in a training programme in accordance with this document, students shall be
qualified in accordance with ISO 24806.
5.2 Minimum age
The minimum age to participate in a training programme in accordance with this document shall be
18 years.
5.3 Diving experience
Students shall have logged at least 100 dives with a minimum of 100 hours using a rebreather. At least
50 dives and 50 hours shall have been made with the same specific rebreather unit to be used in the
course. Concerning these dives:
— a minimum of 30 rebreather dives shall have been made to a depth deeper than 30 m;
— at least 10 of these 30 dives shall have been made to a depth deeper than 50 m using a gas mix
containing helium and requiring decompression stops; these dives shall have been completed after
qualification as a 60 m rebreather diver in accordance with ISO 24806.
The student shall have dived with the rebreather unit within the 6 months prior to starting the course.
5.4 Health requirements
Documented evidence shall be obtained that the student has been medically screened as suitable for
recreational diving by means of an appropriate questionnaire or medical examination.
NOTE See Reference [3] for an example of a medical questionnaire and accompanying guidance to physicians.
In case of doubt, the training service provider shall refer students to proper medical resources. If the
student is not examined by a physician, the student shall be obliged to confirm by signature that he or
ISO 24807:2023(E)
she has understood written information given by the instructor on diseases and physical conditions
which can pose diving-related risks.
Students shall be advised of the importance of appropriate regular medical examinations.
6 Introductory information
Information in accordance with ISO 24803 shall be made available to the students prior to or during the
first class or meeting.
In particular, the students shall be informed of the limits of their training and qualification as specified
in accordance with Clause 4.
7 Theoretical knowledge
7.1 Knowledge review
The training programme shall ensure that knowledge in accordance with ISO 24806 is reviewed by
assessing the students (e.g. by means of an exam or quiz) before teaching new knowledge. Where
knowledge gaps are identified, remedial training shall be carried out.
7.2 Risk management
The training programme shall ensure that students have knowledge concerning the identification,
potential consequences and management of the following risks, specifically related to decompression
dives to 100 m:
— risks associated with each phase of the dive, from dive planning to exiting the water;
— risks associated with hypoxic gas mixtures;
— use of bailout valve when using hypoxic gas mixtures at shallow depths or at the surface;
— risks associated with carrying multiple gases in multiple cylinders;
— failure to follow decompression model ascent rates;
— no direct or immediate access to the surface in an emergency due to decompression requirements
and/or distance;
— inadequate bailout options;
— hypoxia, hyperoxia and hypercapnia, leading to unresponsiveness and drowning due to switching
to the wrong gas, improper gas choice, failing to properly analyse the gas or rebreather system
problems;
— inert gas narcosis;
— omitted procedures and errors caused by extensive equipment task overloading, high physical
exertion and/or psychological loading;
— taking untried equipment and/or configurations on a deep dive without prior testing and
familiarisation in shallow water;
— overweighting or loss of buoyancy;
— dive team members not adequately prepared or proficient;
— dive plan incomplete and without sufficient contingencies;
ISO 24807:2023(E)
— inadequate surface support for the planned dive;
— loss of critical gases (breathing loop and supply gases);
— separation from dive team;
— separation of the dive team from surface support;
— remote dive site.
The training programme shall ensure that students have knowledge concerning the following means
and measures to mitigate risks:
— dive team assessment and readiness;
— dive team proficiency;
— dive plan and roles;
— equipment preparation and testing;
— suitable surface support personnel, procedures and equipment;
— emergency evacuation plan.
7.3 Team diving
The training programme shall ensure that students have knowledge concerning the following potential
risks of diving:
— in mixed teams using different rebreathers;
— in mixed teams using different breathing gases and/or equipment configurations;
— in mixed teams of open-circuit and rebreather divers;
— when team members use different dive and emergency procedures.
The training programme shall ensure that students have the following knowledge concerning diving in
teams:
— team member selection, including considerations of physical and mental fitness;
— awareness of factors that can impact divers’ ability to perform under stress;
— causes of stress (e.g. time pressure, peer pressure, task loading);
— the importance of having a non-judgmental team culture and a willingness to identify problems
without fear or recrimination;
— team protocols and objectives;
— selection of gradient factors or decompression models;
— task assignments between team members;
— team gas analysing and cylinder-marking protocols;
— surface support and support divers;
— communication procedures between team members, surface support and support divers.
ISO 24807:2023(E)
7.4 Project dives with specific objectives
Rebreather dives as deep as 100 m are complex operations and can involve situations in which a group
of divers are diving with a particular purpose, especially exploration, that involves substantially more
complex logistical and dive planning considerations than typical recreational dives. Rebreather divers
at this level need the knowledge necessary to take part in such dives and function properly as part of a
team.
NOTE This kind of diving can also be known as expedition diving.
The training programme shall ensure that students have the following knowledge concerning project
dives:
— advantages and disadvantages of having standardised gases and decompression protocols;
— selection and duties of safety divers;
— surface support and logistics;
— decompression stations (e.g. trapeze, hang bars or habitats);
— ascent lines, descent lines;
— diver accounting procedures (e.g. by use of tags);
— emergency protocols.
7.5 Function of rebreather components
The training programme shall ensure that students have knowledge concerning the function of the
following components of a rebreather, with emphasis on the specific features of the rebreather unit
they will use during their training, specifically relating to decompression dives to 100 m:
— scrubber material suitability for deep diving and why it must be selected in accordance with the
rebreather manufacturer’s specifications, as scrubber performance becomes much more critical as
depth approaches 100 m;
— the need to use a freshly filled scrubber canister for more extreme dives (e.g. dives approaching
100 m in depth or of extended duration);
— gas supplies (including, where applicable, oxygen, diluent or other supply gases);
— gas addition valves [including, where applicable, manual, automatic diluent valve (ADV) or other
automatic gas addition];
— mouthpiece, dive surface valve (DSV);
— bailout valve (BOV);
— displays [including, where applicable, handsets, head-up display (HUD) or other];
— control modules;
— alarm and warning systems;
— firmware, software, including updates and downloads of dive profiles;
— suitability of regulator(s);
— access to gas cylinder valves;
— cylinder pressure indicators;
ISO 24807:2023(E)
— PO monitoring systems;
— CO and helium monitoring systems.
7.6 Breathing performance using a rebreather
The training programme shall ensure that students have knowledge concerning the following factors
affecting breathing performance using a rebreather, specifically relating to decompression dives to
100 m:
— choice of gases (see also Annex A), maximum and minimum depth of gases and advantages of helium;
— gas density (see also Annex A);
NOTE Limiting gas density will ensure that narcotic effects of breathing gas, often expressed as
equivalent narcotic depth (END), remain within acceptable limits.
— ventilation rate and ventilation volume of the diver;
— rebreather design (e.g. rebreather type, rebreather unit, rebreather model), including the advantages
and limitations of different types of rebreathers, in particular their gas control systems, with
particular attention to the limitations of the rebreather used on the course.
7.7 Rebreather assembly and checks
The training programme shall ensure that students have knowledge concerning the following aspects
of rebreather assembly and checks (as applicable to the specific rebreather unit used for training),
specifically relating to decompression dives to 100 m:
— use of unit checklist(s);
— battery power;
— oxygen sensors (e.g. age, integrity and calibration);
— helium sensors, CO monitoring systems;
— control systems and backup computer setup and function;
— PO monitoring and control;
— set-point selection;
— set-point switch depths;
— set-point switch method (manual or automatic);
— on-board and off-board gases programmed into the control system;
— decompression conservatism settings (e.g. gradient factors) programmed into the control system;
— scrubber canister duration, proper preparation for diving, including filling and seals;
— mouthpiece valve operation, bite integrity and security, e.g. mouthpiece retaining strap (MRS);
— gas supplies (composition and pressure of all gases);
— gas connections and feeds to the system;
— bailout system, including multiple off-board cylinders;
— breathing loop integrity, including positive and negative pressure tests;
— displays and warning systems;
ISO 24807:2023(E)
— buoyancy compensator fit, function and adequate lift capacity;
— harness assembly and adjustment with regard to additional off-board cylinders.
7.8 Gas supply duration
The training programme shall ensure that students have knowledge concerning the following factors
affecting the gas supply duration, specifically relating to decompression dives to 100 m:
— frequent activation of gas addition valves;
— mask clearing;
— flushing the breathing loop;
— frequent changes in depth;
— inflating a drysuit and buoyancy compensation device (BCD) (if fed from the rebreather gas supply);
— the effects of system gas leaks.
7.9 CO absorbent duration
The training programme shall ensure that students are knowledgeable about the importance of using
the scrubber in accordance with manufacturer’s instructions and factors that could adversely affect
canister duration, such as:
— cold water temperatures;
— water ingress;
— depth and gas density;
— work rate;
— absorbent material and grain size.
7.10 Rebreather pre-water entry checks
The training programme shall ensure that students have knowledge concerning the following aspects
of rebreather pre-water entry checks:
— use of manufacturer’s rebreather unit checklist(s);
— recalibration of the rebreather unit (if required);
— gas supplies pressurized and on or off as appropriate;
— bailout and off-board cylinder access and operation;
— inflation and deflation systems access and operation (e.g. gas addition valves, BCD; dry suit,
counterlung over pressure valve);
— electronics on;
— confirming inspired oxygen level (e.g. PO or FO );
2 2
— pre-breathing the rebreather.
ISO 24807:2023(E)
7.11 Advanced decompression dive planning
The training programme shall ensure that students have appropriate knowledge concerning the
planning of dives using a rebreather, specifically relating to decompression dives to 100 m, including:
— operational planning, including contingency planning;
— supply gas selection, taking into account the addition of helium to the breathing gas, gas density,
PO , narcotic effects;
— managing oxygen toxicity, including central nervous system (CNS) toxicity and oxygen toxicity units
(OTU);
— absorbent canister duration;
— decompression planning, including knowledge of different decompression models and how to add
conservatism (e.g. gradient factors);
— gas managemen
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