Section 3.00 – Diving Equipment

3.10 General Policy

All equipment must meet standards as determined by the DSO and the DCB.  All equipment must be regularly examined by the person using it and serviced according to manufacturer recommendations.  Equipment that is subjected to extreme usage under adverse conditions should require more frequent testing and maintenance.

3.20 Equipment

The MBL’s DCB must establish the minimum equipment configuration for all dives.

Regulators and Gauges

  • Scuba regulators and gauges must be inspected and tested prior to each use and serviced, at a minimum, according to manufacturer’s recommendations
  • Standard open circuit (OC) regulator configuration is:
    • A first stage
    • Primary 2nd stage
    • Back up 2nd stage
    • Submersible Pressure Gauge (SPG)
    • Inflator hose for a Buoyancy Compensator Device
  • A Full Face Mask may be used in place of the primary 2nd stage according to manufacturer’s recommendations

Equipment for Determination of Decompression Status

  • Each member of the buddy team must have an underwater timing device and depth indicator, or dive computer
  • If dive tables are being used a set must be available at the dive location
  • If a dive computer is used the diver must use the same computer used on repetitive dives.
  • In an aquarium or other manmade structure of a known maximum obtainable depth:
  • A depth indicator is not required, except when a diver’s decompression status must be taken into consideration on repetitive dives.
  • Only one buddy must be equipped with a timing device.
  • The maximum obtainable depth of the aquarium must be used as the diving depth.

Scuba Cylinders

  • Scuba cylinders must be designed, constructed, and maintained in accordance with the applicable provisions of the Unfired Pressure Vessel Safety Orders.
  • Scuba cylinders must be hydrostatically tested in accordance with DOT standards.
  • Scuba cylinders must have an internal and external inspection at intervals not to exceed 12 months.
  • Scuba cylinder valves must be functionally tested at intervals not to exceed 12 months.

Buoyancy Compensation Devices (BCD)

  • Each diver must have the capability of achieving and maintaining neutral buoyancy underwater and positive buoyancy at the surface.
  • BCDs, dry suits, or other variable volume buoyancy compensation devices must be equipped with an exhaust valve.
  • These devices must be functionally inspected and tested at intervals not to exceed 12 months.
  • BCDs, dry suits, or other variable volume buoyancy compensation devices must not be used as a lifting device in lieu of lift bags.

3.30 Auxiliary Equipment

Handheld Underwater Power Tools

  • Power tools and equipment used underwater must be specifically approved for this purpose.
  • Tools and equipment supplied with power from the surface must be de-energized before being placed into or retrieved from the water.
  • Handheld power tools must not be supplied with power from the dive location until requested by the diver.

3.40 Support Equipment

First Aid Supplies

  • A first aid kit and emergency oxygen appropriate for the diving being conducted must be available at the dive site.

Diver’s Flag

  • A diver’s flag must be displayed prominently whenever diving is conducted under circumstances where required or where water traffic is probable.

Compressor Systems – Organizational Member Controlled

The following will be considered in design and location of compressor systems:

  • Low-pressure compressors used to supply air to the diver if equipped with a volume tank must have a check valve on the inlet side, a relief valve, and a drain valve.
  • Compressed air systems over 500 psig must have slow-opening shut-off valves.
  • All air compressor intakes must be located away from areas containing exhaust or other contaminants.

3.50 Equipment Maintenance

Record Keeping

Each equipment modification, repair, test, calibration, or maintenance service must be logged, including the date and nature of work performed, serial number of the item (if applicable), and the name of the person performing the work for the following equipment:

  • Regulators
  • Gauges (SPG, Depth Gauges, Timers, and Dive Computers)
  • BCDs
  • Dry suits
  • Scuba cylinders and valves
  • Full Face Masks
  • Compressors, air filtration systems, gas control panels, and storage banks
  • Surface supplied equipment
  • Rebreather systems
  • Additional equipment categories as determined by the DCB

Compressor Operation and Air Test Records

Gas analyses and air tests must be performed on each MBL-controlled breathing air compressor at regular intervals of no more than 100 hours of operation or 6 months, whichever occurs first.  The results of these tests must be entered in a formal log and be maintained.

3.60 Air Quality Standards

Breathing Gas

Breathing gas must meet the following specifications as set forth by the Compressed Gas Association (CGA Pamphlet G-7.1; see table below).

CGA Grade E
Component Maximum
Oxygen 20 – 22%/v
Carbon Monoxide 10 PPM/v
Carbon Dioxide 1000 PPM/v
Condensed Hydrocarbons 5 mg/m3
Total Hydrocarbons as Methane 25 PPM/v
Water Vapor ppm (2)
Objectionable Odors None

For breathing air used in conjunction with self-contained breathing apparatus in extreme cold where moisture can condense and freeze, causing the breathing apparatus to malfunction, a dew point not to exceed -50°F (63 pm v/v) or 10 degrees lower than the coldest temperature expected in the area is required.

Remote Operations

For remote site operations using gas sources not controlled by the MBL, every effort should be made to verify breathing gas meets the requirements of this standard. If CGA Grade E gas is not verifiable, the DCB must develop a protocol to mitigate risk to the diver.