The diving regulation (O. Reg. 629/94: Diving Operations) describes the duties and responsibilities of employers, employees, contractors and owners, to ensure that commercial diving in Ontario is done safely.

The diving regulation applies to all diving operations, except:

  • federally regulated diving operations
  • recreational diving, including recreational diver training
  • any diving operation where the only underwater breathing equipment used is a snorkel
  • any dive by an unpaid volunteer related to an unforeseen emergency response

This resource does not replace the Occupational Health and Safety Act (OHSA) and its regulations and should not be used as or considered legal advice. Health and safety inspectors apply and enforce these laws based on the facts they find in the workplace.

Your duties as the owner who is hiring a diver or diving contractor

When you hire a diver or diving contractor for a job, including retrieving property, underwater filming, scientific diving, to build anything, or to inspect or repair your property, you have many of the same responsibilities of constructors and employers engaged in a diving operation.

Prepare required notices and plans

You must:

  • complete a Notice of Diving Operations and file it with the Ministry of Labour, Immigration, Training and Skills Development. The written notice must be provided at least 24 hours before the diving operation begins It can also be provided orally at least 24 hours before the diving operation begins if written notice is also provided within 5 days of the dive beginning.
  • notify appropriate authorities, industrial plants operating within 2km of the diving operation and water control facilities that are within 1km the diving operation, and that might affect the safety of a worker associated with the diving operation
  • prepare a written operational plan for the diving operation, which must describe:
    • the tasks to be performed in the diving operation
    • how those tasks are to be performed
    • how the hazards that could be encountered in the diving operation are to be identified and handled
    • which agencies, plants and facilities will be given notice
  • prepare a written contingency plan for the diving operation, which must include:
    • instructions for communicating with medical assistance in the event of an emergency
    • emergency procedures for the evacuation of an injured diver from the dive site
    • emergency procedures for responding to any significant failure of a component of any diving equipment
    • emergency procedures for responding to a loss of communications with a diver
    • emergency procedures for responding to hazardous weather or ice conditions
    • emergency procedures for aborting a dive
    • emergency procedures for responding to any inability of an offshore dive site to maintain station

Identify hazards

You must:

  • identify and lock-out or adequately control all hazardous water flows
  • identify any contaminants that might pose a hazard to a diver and prepare a management plan
  • deal with all hazardous mechanisms, before a diver approaches them in accordance with clause 4.5.4 of CSA Standard Z275.2-11, Occupational Safety Code for Diving Operations. That means that the diving supervisor must:
    • secure all mechanisms against inadvertent movement
    • have those mechanisms locked out (in accordance with CAN/CSA-Z460)
    • ensure the mechanisms are locked out in a manner that is satisfactory to the diver and the diving supervisor

At the dive site

You must have copies of the:

  • written diving notice (or in instances where written notice has not yet been given, a written statement including the date of the oral notice and the name of the person to whom the oral notice was given)
  • operational plan
  • contingency plan
  • regulation
  • CSA standards referenced in the regulation

When the dive is taking place there must be at least one competent person appointed as a supervisor, and at least one supervisor must be present at the dive site whenever diving operations are being conducted.

Working as a commercial diving contractor

As a commercial diver or diving contractor you share the duties of owners and you have other specific duties.

About the person who is diving

Every person who participates in a diving operation must be:

  • competent for the type of diving operation that they are participating in
  • medically fit

Competency requirements

Diver competency requirements are prescribed by the diving regulation, which requires an employer to ensure that every person who participates in a diving operation meets the competency requirement applicable to the type of diving operation in question as set out in the CSA Standard Z275.4-12. Learn about the competency standard for diving, hyperbaric chamber and remotely operated vehicle operations (CSA Standard Z275.4-12).

Medical fitness

A doctor who is knowledgeable about diving medicine and hyperbaric medicine can determine if a diver is medically fit. Medical fitness is determined in accordance with the Code for the Medical Examination of Divers.

The Diver Certification Board of Canada (DCBC) publishes a list of physicians who are qualified to conduct the medical examination of commercial divers, but the list is not vetted by the Ministry of Labour, Immigration, Training and Skills Development. The employer, worker (diver) and constructor, if the diving operation is being conducted on a project, are responsible for making sure that they seek the services of a doctor that meets the requirements set out in the Code for the Medical Examination of Divers.

At the dive site

Employers and supervisors must make sure that all necessary documents are kept at the dive site, including:

  • any operation manuals, field manuals, maintenance manuals or written material necessary for adequate dive site management
  • alerts
  • safety checklists

There must be adequate means of communication for the type of dive listed in the regulation

Learn what means of communication are required.

The dive supervisor must also ensure that there is adequate 2-way communication connecting the dive site with medical assistance.

The dive supervisor must ensure there is an adequate means of access to, and getting out of, the water.

Equipment at the site

All equipment necessary for the dive and listed in the regulation must be provided and maintained in good condition. Find out what equipment is necessary.

When required by the regulation, there must be a hyperbaric chamber at the dive site.

Breathing equipment

The diving supervisor must make sure:

People present during the dive

Every diving supervisor, diver and at least one diver’s tender at the dive site must hold up-to-date certification in CPR (cardio-pulmonary resuscitation), oxygen administration and first aid.

Depending on the type of diving operation you must:

  • meet minimum crew requirements for S.C.U.B.A. or surface supply
  • be able to perform emergency rescue and evacuation of divers
  • ensure accurate detailed records are kept of divers’ logbooks and daily diving activities

Become a commercial diver

Recreational divers who wish to work as commercial divers must first undergo the assessment and training procedures laid out by the DCBC.

The DCBC maintains a list of approved commercial diver training facilities and assessors.

Report incidents

The employer must notify the Ministry of Labour, Immigration, Training and Skills Development, in writing, within two days of any incidents listed in the Ontario Regulation 420/21.

Find out what incidents are listed in the regulation.

To avoid problems or interruptions in the work, it is also recommended that you hire a diver or diving contractor who is qualified to perform the work.

Doctors who work with divers

People who wish to work as commercial divers in Ontario must undergo periodic medical examinations by a doctor who is knowledgeable about diving medicine and hyperbaric medicine.  The medical examinations must be performed in accordance with the Code for the Medical Examination of Divers.

Examinations must take place:

  • every two years for divers under age 40
  • every year for divers age 40 or older
  • more frequently if recommended by the examining doctor

Before diving, a potential diver must get a statement from the examining doctor that states the person is fit to dive or fit to dive with limitations.

Doctor knowledge and competency

To perform medical examinations of people wishing to work as commercial divers, ensure that you meet requirements for doctor knowledge and competency as outlined in the Code for Medical Examination of Divers, and be prepared to give clients this information when asked.

Examinations must be conducted by a doctor with basic training in diving medicine who is capable of screening workers for exposure to atmospheric pressure. The doctor must:

  • be licensed to practice in Ontario
  • have completed a basic training course in diving medicine
  • have an effective current working knowledge of the physical laws affecting the diver and the underwater operation through continuing medical education
  • have an understanding of the interaction that occurs between these physical laws and the diver’s physiology and of the implications of this interaction for the diver
  • have sufficient awareness of the pathological conditions that can arise as a consequence of exposure to pressure
  • have the ability to perform a competent physical evaluation of diving candidates, divers and caisson workers

Examination requirements

As the examining doctor, you must ensure that you follow the examination requirements detailed under the Code for the Medical Examination for Divers, including the five elements of the exam:

  • medical and occupational history
  • physical examination
  • clinical tests
  • determination of fitness
  • health education

You may have patients and clients who would like you to examine them to ensure that they are fit to dive in accordance with provincial regulations.

What patients and clients should give you

As an examining physician, you can expect your patients and clients to provide you with all the information you need to decide whether they are fit to dive, including:

The Ministry of Labour, Immigration, Training and Skills Development does not certify physicians to do diving examinations. We do not keep a list of approved physicians.

Special hazards in diving

Injuries sustained by commercial divers are usually fatal. A lack of operational and contingency planning is often the root cause of diving accidents.

Divers are at risk if hazards are not identified and adequately handled, and if emergency management measures and procedures are not in place.

Identify delta P (ΔP) or differential pressure hazards

There are many water flow hazards that may affect a diving operation.

Differential pressure, known as "Delta P” or (ΔP) can present unique and deadly hazards to divers. Differential pressures can happen when two bodies of water intersect, each with a different water level, such as at a dam. The pressure forces can be considerable when the water flows from a high-pressure area to a low-pressure area. A diver working on the high-pressure side may be drawn into the flow and trapped. Serious injuries or death may occur.

Many occupational diving incidents in Ontario have occurred at water control structures such as dams, intakes and other structures built to control water levels. These incidents might have been prevented if owners, employers and diving supervisors had taken every reasonable precaution in the circumstances to protect workers, including putting in place adequate measures and procedures to identify and control (ΔP) hazards.

Delta P hazards must be identified before the dive begins because once a diver is drawn into the hazard it is usually too late to conduct a rescue.

Before a dive begins, any water flow that may be a hazard to a diver must be identified. Use the test methods described in the 2011 Guideline for Diving Operations on Dams and Other Worksites where Delta-P Hazards May Exist to identify water flow hazards.

All identified water flow hazards must be locked-out or controlled in a manner that is satisfactory to the diver and the diving supervisor, and ensures that the water flow poses no safety hazard to the diver.

Resources for the diving industry

Dive site personnel training and certification

Medical examination of divers

Test methods for identifying Delta P (ΔP) hazards