Predive procedures for scuba operations include equipment preparation, diver
preparation, and conducting a predive inspection before the divers enter the water.
Prior to any dive, all divers must carefully inspect their
own equipment for signs of deterioration, damage, or corrosion. The equipment
must be tested for proper operation. Predive preparation procedures must be standardized,
not altered for convenience, and must be the personal concern of each
diver.
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Inspect air cylinder exteriors and valves for rust, cracks, dents, and any
evidence of weakness.
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Inspect O-ring.
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Verify that the reserve mechanism is closed (lever in up position) signifying a
filled cylinder ready for use.
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Gauge the cylinders according to the following procedure:
1. Attach pressure gauge to O-ring seal face of the on/off valve.
2. Close gauge bleed valve and open air reserve mechanism (lever in down
position). Slowly open the cylinder on/off valve, keeping a cloth over the
face of the gauge.
3. Read pressure gauge. The cylinder must not be used if the pressure is not
sufficient to complete the planned dive.
4. Close the cylinder on/off valve and open the gauge bleed valve.
5. When the gauge reads zero, remove the gauge from the cylinder.
6. Close the air reserve mechanism (lever in up position).
7. If the pressure in cylinders is 50 psi or greater over rating, open the
cylinder on/off valve to bleed off excess and regauge the cylinder.
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Check the condition of the weight belt.
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Make sure that the proper number of weights are secure and in place.
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Verify that the quick-release buckle is functioning properly.
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Ensure wrist watch is wound and set to the correct time.
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Inspect the pins and strap of the watch for wear.
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Inspect pins and straps.
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If possible, check compass with another compass.
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Make comparative checks on depth gauges to ensure depth gauges read zero
fsw on the surface.
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Inspect any other equipment that will be used on the dive as well as any spare
equipment that may be needed during the dive including spare regulators,
cylinders, and gauges.
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Check all protective clothing, lines, tools, flares, and other optional gear.
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Check for signs of rot and excessive wear.
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Adjust straps for individual use and test quick-release mechanisms.
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Check backpack for cracks and other unsafe conditions.
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Check the hoses for cracks and punctures.
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Test the connections of each hose at the regulator and mouthpiece assembly by
tugging on the hose.
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Check the clamps for corrosion and damage; replace as necessary and in
accordance with PMS procedures.
1. Attach regulator to the cylinder manifold, ensuring that the O-ring is properly
seated.
2. Crack the cylinder valve open and wait until the hoses and gauges have
equalized.
3. Next open the cylinder valve completely and then close (back off) one-quarter
turn.
4. Check for any leaks in the regulator by listening for the sound of escaping air.
If a leak is suspected, determine the exact location by submerging the valve
assembly and the regulator in a tank of water and watch for escaping bubbles.
Frequently the problem can be traced to an improperly seated regulator and is
corrected by closing the valve, bleeding the regulator, detaching and reseating.
If the leak is at the O-ring and reseating does not solve the problem, replace
the O-ring and check again for leaks.
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Orally inflate preserver to check for leaks and then squeeze out all air. The
remaining gas should be removed after entry into the water by rolling onto the
back and depressing the oral inflation tube just above the surface. Never suck
the air out, as it may contain excessive carbon dioxide.
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Inspect the carbon dioxide cartridges to ensure they have not been used (seals
intact) and are the proper size for the vest being used and for the depth of dive.
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The cartridges shall be weighed in accordance with the Planned Maintenance
System.
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The firing pin should not show wear and should move freely.
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The firing lanyards and life preserver straps must be free of any signs of
deterioration.
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When the life preserver inspection is completed, place it where it will not be
damaged. Life preservers should never be used as a buffer, cradle, or cushion
for other gear.
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Check the seal of the mask and the condition of the head strap.
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Check for cracks in the skirt and faceplate.
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Check straps for signs of cracking.
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Inspect blades for signs of cracking.
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Test the edge of the knife for sharpness
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Test the edge of the knife for sharpness
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Verify that the knife can be removed from the scabbard without difficulty, but
will not fall out.
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Inspect the snorkel for obstructions.
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Check the condition of the mouthpiece.
When the divers have completed inspecting and
testing their equipment, they shall report to the Diving Supervisor. The divers shall
be given a predive briefing of the dive plan. This briefing is critical to the success
and safety of any diving operation and shall be concerned with only the dive about
to begin. All personnel directly involved in the dive should be included in the
briefing. Minimum items to be covered are:
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Dive objectives
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Time and depth limits for the dive
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Task assignments
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Buddy assignments
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Work techniques and tools
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Phases of the dive
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Route to the work site
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Special signals
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Anticipated conditions
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Anticipated hazards
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Emergency procedures (e.g., unconscious diver, trapped diver, loss of air,
aborted dive, injured diver, lost diver, etc.)
When the Diving Supervisor determines all requirements for the dive have been
met, the divers may dress for the dive.
Although scuba divers should be able to put on all gear themselves,
the assistance of a tender is encouraged. Dressing sequence is important as the weight belt must be outside of all backpack harness straps and other equipment
in order to facilitate its quick release in the event of an emergency. The following
is the recommended dressing sequence to be observed:
1. Protective clothing. Ensure adequate protection is provided with a wet suit.
2. Booties and hood.
3. Dive knife.
4. Life preserver, with inflation tubes in front and the actuating lanyards exposed
and accessible.
5. Scuba. Most easily donned with the tender holding the cylinders in position
while the diver fastens and adjusts the harness. The scuba should be worn
centered on the diver’s back as high up as possible but not high enough to
interfere with head movement. All quick-release buckles must be positioned
so that they can be reached by either hand. All straps must be pulled snug so
the cylinders are held firmly against the body. The ends of the straps must
hang free so the quick-release feature of the buckles will function. If the straps
are too long, they should be cut and the ends whipped with small line or a
plastic sealer. At this time, the cylinder on/off valve should be opened fully
and then backed off one-quarter to one-half turn. Ensure buoyancy
compensator whip is connected to the buoyancy compensator.
6. Accessory equipment (diving wrist watch, depth gauge, snorkel).
7. Weight belt.
8. Gloves.
9. Swim fins.
10. Face mask or full face mask.
The divers must report to the Diving Supervisor for a final
inspection. During this final predive inspection the Diving Supervisor must:
1. Ensure that the divers are physically and mentally ready to enter the water.
2. Verify that all divers have all minimum required equipment (scuba, face mask,
life preserver or buoyancy compensator, weight belt, dive knife, scabbard,
swim fins, watch and depth gauge). When diving scuba and a buddy line is
used, only one depth gauge and one watch per dive team is requ
3. Verify that the cylinders have been gauged and that the available volume of air
is sufficient for the planned duration of the dive.
4. Ensure that all quick-release buckles and fastenings can be reached by either
hand and are properly rigged for quick release.
5. Verify that the weight belt is outside of all other belts, straps, and equipment
and will not become pinched under the bottom edge of the cylinders.
6. Verify that the life preserver or buoyancy compensator is not constrained and
is free to expand, and that all air has been evacuated.
7. Check position of the knife to ensure that it will remain with the diver no
matter what equipment is left behind.
8. Ensure that the cylinder valve is open fully and backed off one-quarter to onehalf
turn.
9. Ensure that the hose supplying air passes over the diver’s right shoulder and
the exhaust hose on the double-hose unit passes over the left shoulder. Doublehose
regulators are attached so that the exhaust ports face up when the tank is
standing upright.
10. With mouthpiece or full face mask in place, breathe in and out for several
breaths, ensuring that the demand regulator and check valves are working
correctly..
11. With a single-hose regulator, depress and release the purge button at the
mouthpiece and listen for any sound of leaking air. Breathe in and out several
times ensuring valves are working correctly.
12. Give the breathing hoses and mouthpiece a final check; ensure that none of the
connections have been pulled open during the process of dressing.
13. Check that the air reserve mechanism lever is up (closed position).
14. Conduct a brief final review of the dive plan.
15. Verify that dive signals are displayed and personnel and equipment are ready
to signal other vessels in the event of an emergency.
