Study your flashcards anywhere!

Download the official Cram app for free >

  • Shuffle
    Toggle On
    Toggle Off
  • Alphabetize
    Toggle On
    Toggle Off
  • Front First
    Toggle On
    Toggle Off
  • Both Sides
    Toggle On
    Toggle Off
  • Read
    Toggle On
    Toggle Off

How to study your flashcards.

Right/Left arrow keys: Navigate between flashcards.right arrow keyleft arrow key

Up/Down arrow keys: Flip the card between the front and back.down keyup key

H key: Show hint (3rd side).h key

A key: Read text to speech.a key


Play button


Play button




Click to flip

56 Cards in this Set

  • Front
  • Back
Can u make a planned decompression dive in SCUBA?
Decompression diving using open-circuit air SCUBA may be undertaken only if no other option exists and only with the concurrence of the Commanding Officer or Officer-in-Charge (OIC).
At a minimum, each diver must be equipped with the following items to safely conduct an open-circuit SCUBA dive:
Open-circuit SCUBA, Face mask, Life preserver/buoyancy compensator, Weight belt and weights as required, Knife, Swim fins, Submersible pressure gauge or Reserve J-valve, Submersible wrist watch, Only one is required when diving in pairs with a buddy line, Depth gauge, Octopus.
Open-circuit SCUBA cylinders must be visually inspected at least:
Once every 12 months and every time water or particulate matter is suspected in the cylinder.
How often are SCUBA cylinders hydrostatically tested?
Every 5 years.
What is the minimum size SCUBA cylinder authorized for navy use?
Fifty cubic feet
When is it authorized to dive without a submersible pressure gauge?
When there is a j-valve installed
The dive must be terminated when the cylinder pressure reaches ____ psi for a single cylinder or ____ psi for twin manifold cylinders.
500 & 250
What is the difference between a life preserver and buoyancy compensator?
The life preserver must be sturdy enough to resist normal wear and tear, and of sufficient volume to raise an unconscious diver safely from maximum dive depth to the surface. Most life preservers currently in use employ carbon dioxide (CO2) cartridges to provide inflation in an emergency
As a buoyancy compensating device, the compensator can be inflated by a low-pressure inflator connected to the first-stage regulator, or an oral inflation tube. Any buoyancy compensator selected for Navy use must have an over-pressure relief valve.
At the dive supervisor’s discretion, when using a_____, a Buoyancy Compensator is not required.
variable volume dry suit (VVDS)
What are the characteristics / requirements of a knife?
Knives may have single- or double-edged blades with chisel or pointed tips. The most useful knife has one sharp edge and one saw-toothed edge. All knives must be kept sharp. The knife must be carried in a suitable scabbard and worn on the diver’s life preserver, hip, thigh, or calf. The knife must be readily accessible, must not interfere with body movement, and must be positioned so that it will not become fouled while swimming or working. The scabbard should hold the knife with a positive but easily released lock. The knife and scabbard must not be secured to the weight belt. If the weights are released in an emergency, the knife may be also dropped unintentionally.
What are three basic types of lifelines?
the tending line, the float line, and the buddy line.
What are the tending requirements for a single diver?
A single diver will be tended with either a tending line or a float line. When direct access to the surface is not available a tending line is mandatory. A float line may not be used.
- Low Vis/night, displacement from dive site
What are the characteristics of a tending line?
The line should be strong and have neutral or slightly positive buoyancy. Nylon, Dacron, and manila are all suitable materials. Always attach a lifeline to the diver, never to a piece of equipment that may be ripped away or may be removed in an emergency.
Buddy lines are __ to __ feet in length.
Air procured from commercial sources must meet what requirements
Grade A Source I or Source II air
To prevent whipping in the event of hose failure under pressure, the use of a strain relief made of what?
cable, chain, 21-thread, or 3/8-inch nylon, married at a minimum of every 18 inches and at the end of the hose. Marrying cord shall be 1/8-inch nylon or material of equivalent strength. Tie wraps, tape, and marlin are not authorized for this purpose.
Ensure over-bottom pressure of first stage regulator has been set to a minimum of ___ psig or in accordance with manufacturer’s recommendations within the past ____.
135 & year
The greatest single safety practice in Navy SCUBA operations is the use of what?
the buddy system.
The tender should signal the diver with a single pull every __ or __ minutes to determine that the diver is all right.
When using externally powered tools with SCUBA, the diver must have what?
voice communications with the Diving Supervisor.
An EGS is mandatory at depths deeper than __ fsw and when diving inside a wreck or enclosed space.
Planned air dives below ___ fsw require ____________ approval.
190 & CNO
What are the Emergency Gas Supply Requirements for the MK21 and KM37
The EGS system consists of an adequately charged ANU approved SCUBA cylinder with either a K- or J- valve (with reserve turned down) and a first stage regulator set at manufacturer’s recommended pressure, but not lower than 135 psig. A relief valve set at 180 ± 5 psig over bottom pressure must be installed on the first stage regulator to prevent rupture of the low pressure hose should the first stage regulator fail. A submersible pressure gauge is also required on the first stage regulator. For enclosed space diving an extended EGS whip 50 to 150 feet in length may be used. If the diving scenario requires the EGS topside, adjust the first stage regulator to 135 psi over bottom pressure.
What is the definition of an adequately charged SCUBA cylinder?
the pressure that provides sufficient air to bring the diver to his first decompression stop or the surface for no-decompression dives.
The MK 20 MOD 0 is authorized for use to a depth of ___ fsw with surface-supplied air.
What are the EGS Requirements for MK 20 MOD 0?
An adequately charged ANU approved SCUBA cylinder with either a K- or J-valve.
An approved SCUBA regulator set at manufacturer’s recommended pressure, but not lower than 135 psi, with an extended EGS whip 50 to 150 feet in length. If the diving scenario dictates leaving the EGS topside, adjust the first stage regulator to 150 psig.
An approved submersible pressure gauge.
The EXO BR MS is a commercial-off-the-shelf, full face mask, manufactured by Kirby Morgan Dive Systems, which is used for surface-supplied diving. It is authorized for use to ___ fsw on air.
What does a MK 3 LWDS flask rack consist of?
Each rack has 3 flasks which are (0.935 cu ft floodable volume each). Each flask holds 191 scf of compressed air at 3,000 psi.
Describe the MK 3 MOD 0 Configuration 1.
Air is supplied by a medium-pressure diesel driven compressor unit supplying primary air to the divers at 18 standard cubic feet per minute (scfm) with secondary air being supplied by one air-rack assembly. Total available secondary air is 594 scf.
Describe the MK 3 MOD 0 Configuration 2.
Primary air is supplied to the divers using three flask rack assemblies. Secondary air is supplied by one flask rack assembly. Total available primary air is 1,782 scf at 3,000 psi. Total available secondary air is 594 scf.
Describe the MK 3 MOD 0 Configuration 3.
Primary air is supplied to the divers using three flask rack assemblies. Secondary air is supplied by two flask rack assemblies. Total available primary air is 1,782 scf. Total available secondary air is 1,188 scf.
Describe the MK 3 MOD 1 Lightweight Dive System.
This system is identical to the MK 3 MOD 0 LWDS except that the control console and volume tank have been modified to support 5,000 psi operations for use with the Air Supply Rack Assembly (ASRA). With appropriate adapters the system can still be used to support normal LWDS operations.
Describe the ROPER Diving Cart.
The ROPER diving cart is a trailer-mounted diving system, designed to support one working and one standby diver in underwater operational tasks performed by Ship Repair Activities to 60 fsw. Air supply system. Primary air source of two 6 cu ft, 3,000 psi air flasks; secondary air source of a single 1.52 cu ft, 3,000 psi air flask; and a SCUBA charging station.
Describe the The FADS III.
It is a portable, self-contained, surface-supplied diver life-support system designed to support dive missions to 190 fsw. Compressed air at 5,000 psi is contained in nine 3.15 cu ft floodable volume composite flasks vertically mounted in an Air Supply Rack Assembly (ASRA).
What is the purpose of the Oxygen Regulator Console Assembly (ORCA)?
To provide 100% oxygen to the diver’s umbilical’s for use during in-water oxygen decompression.
What line is recommended for a descent line?
A 3-inch double-braid line is recommended, to prevent twisting and to facilitate easy identification by the diver on the bottom.
What is a circling line?
The circling line is attached to the bottom end of the descent line. It is used by the diver as a guide in searching and for relocating the descent line.
What is a stage line?
Used to raise and lower the stage, the stage line is to be 3-inch double braid, or 3/8-inch wire rope minimum, taken to a capstan or run off a winch and davit.
What are the primary are requirements of a DLSS?
The primary supply must be able to support the air flow and pressure requirements for the diving equipment designated. The capacity of the primary supply must meet the consumption rate of the designated number of divers for the full duration of the dive (bottom time plus decompression time).
What are the secondary air requirements of a DLSS?
The secondary supply must be sized to be able to support recovery of all divers using the equipment and dive profile of the primary supply if the primary supply sustains a casualty at the worst-case time
All valves and electrical switches that directly influence the air supply shall be labeled:
A ______________is required when operating directly from a low pressure air compressor.
volume tank
What type of air compressors are the only compressors authorized for use in Navy air diving operations?
What are the three line pull signals that are not answered immediately?
Two of these, from diver to tender, are “Haul me up” and “Haul me up immediately.” Acknowledgment consists of initiation of the action. The other signal, from the tender to diver, is “Come up.” This signal is not acknowledged until the diver is ready to leave the bottom.
Line Pull Signals From Tender to Diver
1 Pull “Are you all right?” When diver is descending, one pull means “Stop.”
2 Pulls “Going Down.” During ascent, two pulls mean “You have come up too far; go back down until we stop you.”
3 Pulls “Stand by to come up.”
4 Pulls “Come up.”
2-1 Pulls “I understand” or “Talk to me.”
3-2 Pulls“Ventilate.”
4-3 Pulls“Circulate.”
Line Pull Signals From Diver to Tender
1 Pull “I am all right.” When descending, one pull means “Stop” or “I am on the bottom.”
2 Pulls “Lower” or “Give me slack.”
3 Pulls “Take up my slack.”
4 Pulls “Haul me up.”
2-1 Pulls “I understand” or “Talk to me.”
3-2 Pulls “More air”
4-3 Pulls "less air"
Special Signals From the Diver
1-2-3 Pulls “Send me a square mark.”
5 Pulls “Send me a line.”
2-1-2 Pulls “Send me a slate.”
Searching Signals (Without Circling Line)
7 Pulls “Go on (or off) searching signals.”
1 Pull “Stop and search where you are.”
2 Pulls “Move directly away from the tender if given slack; move toward the tender if strain is taken on the life line.”
3 Pulls “Face your umbilical, take a strain, move right.”
4 Pulls “Face your umbilical, take a strain, move left.”
Searching Signals (With Circling Line)
7 Pulls “Go on (or off) searching signals.”
1 Pull “Stop and search where you are.”
2 Pulls “Move away from the weight.”
3 Pulls “Face the weight and go right.”
4 Pulls “Face the weight and go left.”
Emergency Signals From the Diver
2-2-2 Pulls “I am fouled and need the assistance of another diver.”
3-3-3 Pulls “I am fouled but can clear myself.”
4-4-4 Pulls “Haul me up immediately.”
In relation to searching, what is the Jack-Stay method
The jack-stay can be established by laying two large buoys and setting a line between them. A diving launch, with a diver on the bottom, can follow along the line from buoy to buoy, coordinating progress with the diver who is searching to each side of the established base line.
When a diver is working in an enclosed or confined space with the exception of submarine ballast tanks, the Diving Supervisor shall have the diver tended by another diver at the ____________.
access opening
When diving in submarine ballast tanks, the divers shall not remove their diving equipment until what?
the atmosphere has been flushed twice with air from a compressed air source meeting the requirements of Chapter 4, or the submarine L.P. blower, and tests confirm that the atmosphere is safe for breathing. Tests of the air in the enclosed space shall be conducted hourly. If the divers smell any unusual odors they shall immediately don their EGS.
During enclosed space diving, all divers shall be outfitted with what basic equipment?
a MK 21 MOD 1, KM-37, MK 20 MOD 0, or EXO BR MS that includes a diver-to-diver and diver-to-topside communications system and an EGS for the diver inside the space.
Is steel cable or chain authorized for a descent line?
Yes the Diving Officer must approve such use.
The maximum working depth for air diving operations using the MK 21 MOD 1 and KM-37 UBAs is ____ fsw.