Explain Boyle's law and how it relates to diving?
Boyle's law states that at constant temperature, the absolute pressure, and the volume of a gas are inversely related.
This law relates to diving through squeezes, pulmonary over inflation syndrome, air consumption and minimum manifold pressure.
Explain Gay-Lussac's law and how it relates to diving?
Gay-Lussac's law states that at a constant volume, the pressure of a gas is directly related to a change in the absolute temperature.
This law relates to diving through charging, air in storage, and recompression chambers.
Explain Dalton's law and how it relates to diving?
Dalton's law States the total pressure exerted by a mixture of gases is equal to the sum of the pressures of each of the different gases making up the mixture, with each gas acting as if it alone were present and occupied the total volume.
This law relates to diving through gas toxicity at depth and the decompression tables.
Explain Henry's law and how it relates to diving?
Henry's law states the amount of any gas that will dissolve in a liquid at a given temperature is directly related to the partial pressure of that gas. This law relates to diving through gas absorption based on the amount of time spent at a given depth.
Explain the General Gas law?
The General Gas law demonstrates that temperature, volume and pressure affects a gas in a way that a change in one factor will cause a balanced change in one or both of the others.
Explain the Kinetic Theory of gases and how it relates to mixing gases?
The kinetic theory states the kenetic energy of a gas is related to the speed at which the gas molecules are moving.
Gas mixing occurs as a result of constant molecular motion or kinetic activity.
Why is the shallowest part of a dive the most dangerous?
It is the greatest change in volume.
When using a diver held pinger system what is recommended to be worn by the diver?
Standard ¼ neoprene hood for protection.
If a diver must be in the water during explosive operations the pressure he experiences should be less than how many pounds per square inch?
What means of transmitting heat is a diver most concerned with?
Define pressure gradient as it applies to decompression theory?
The pressure gradient is the difference between the gas tension in a liquid and the partial pressure of gas outside the liquid.
What two (physics) conditions greatly affect the quanity of gas absorbed by a liquid?
Temperature and pressure.
What is the rule for diving near active sea suctions?
Diving within 50' of a suction maintaining an intake of 50 gpm or more is not authorized unless it is considered an emergency repair and permission is granted by the respective CO's of the repair activity and the activity being worked on.
Diving less than 50' from a suction intake of less than 50 gpm or diving less than 50' from an intake on the opposite side of the keel with an intake of more than 50gpm is at the discretion of the diving supervisor.
At what water temperature is the use of dry suits or hot water suits recommended?
Below 40 degrees Fahrenheit.
What is the mooring requirement for surface supplied diving operations?
Secured by at least a two-point moor. The exceptions to this rule include a ship moored along side a pier or another vessel that is properly anchored or when a ship cannot anchor due to depth constriction.
What flag shall be flown when diving in the vicinity of small civilian boats?
A red diving sport flag with a white stripe.
What publication states the lights and shapes that must be displayed for diving operations?
Coast Guard Rules and Regulations manual; rule 27.
What temperature is considered ice/cold water diving?
Diving under/near ice cover or in water at or below 37 degrees Fahrenheit.
What are the material requirements for tending lines used for ice/cold water diving?
A polypropylene braided or twisted line that is highly visible and floats will be used. A bowline or D-ring must be spliced in the line and attached to the diver.
Both ends of the line must be absolutely secure and not attached to portable equipment. A (4"x 4" x 2') board placed under the ice several yards away from the hole is a good securing point.
When is a life preserver not required for SCUBA diving?
Diving under ice. Accidental inflation of the preserver may cause head injuries. Its' use is prohibited when diving under ice.
What should divers practice before diving under ice?
Minimum distance from the ships bottom to the sea floor at mean low tide for diving operations?
When you go below the bilge keel or the maximum beam of a submarine the minimum distance is 4' for normal diving operations; however, cleaning operations requires a distance of 6'.
Minimum distance between a ship and a pier for diving and cleaning operations?
When conducting diving operations the minimum distance between a ship and a pier is 3'. The distance for cleaning operations is 5'. The distance between an aircraft carrier and the pier for normal diving operations is 20'.
When diving in biologically contaminated water the diving equipment used must provide what?
Maximum protection consistent with the threat.
At what altitude are the Navy decompression tables designed for?
300' without corrections.
When is a ground fault interrupter required?
GFI's are required when line voltage is above 7.5 VAC or 30 VDC.
What are the range limits for active low frequency sonar?
600 to 3000 yards. One must use the permissible exposure limits chart (PEL) to figure safe diving distance.
State the precautions for diving in an enclosed space.
During enclose space diving, all divers are outfitted with MK-21MOD 1, MK20-MOD O or EXO BR MS that includes a diver to diver and diver to topside communications system and an EGS to the diver inside the space.
What atmospheric requirements are necessary for divers entering submarine ballast tanks?
Before the divers remove their equipment the air must be flushed twice with air from a compressed air source meeting the requirement of Chapter 4, or the submarine L.P. blower. Tests of the air shall be conducted hourly in accordance with NSTM 074, Volume 3.
State the requirements for flying after diving.
Refer to table 9-5. Ascent to altitude after diving chart. However for gas dives the manual requires a12hr wait following a 'no d' dive and 24hrs for decompression dives.
Are SCUBA divers always tended?
No, the use of the buddy system can be used. However, at night time they must wear a buddy line at a minimum
When must a SCUBA diver be tended?
A diver must be tended when it is necessary to exchange signals, keep track of divers location, diving in excessive debris i.e. fishing line, or operate in limited visibility. A single diver must be tended by a tending line or a float line.
Is the use of SCUBA permitted under floating hulls?
SCUBA is permitted with the use of a tending line. Whenever a diver does not have direct access to the surface a tending line must be used.
Are externally powered tools allowed when using SCUBA gear?
Yes, but; the diver must have voice communications with the diving supervisor.
How long is a buddy line and when should it be used?
A buddy line 6 to 10 feet long is used to connect the dive buddies at night, during poor visibility or diving around debris.
Who may authorize the use of an untended SCUBA diver?
An EOD Diving Officer may authorize a single untethered EOD diver in an operational situation.
What are the requirements to conduct a SCUBA dive deeper than 130 FSW?
Permission must be granted by the Commanding Officer or Officer in Charge.
When is an on-site chamber required during diving operations?
When conducting planned air decompression dives deeper than 130 FSW.
Whose permission is required to conduct decompression dives in MK-20 UBA?
Commanding Officer or Officer in Charge.
Whose permission is required to conduct a planned exceptional exposure dive?
The Commanding Officer with CNO approval.
Define "on site chamber" for conducting planned air decompression dives deeper than 130 FSW?
A certified and ready chamber within 30 minutes of the dive site by available transportation.
When is a diving medical officer required to be on-site during air diving operations?
All air dives deeper than 190 FSW, exceeding the max-working limit of the diving apparatus, and exceptional exposure dives.
When is a chase boat required for SCUBA operations?
A chase boat is required whenever the possibility exists that the diver may be displaced from the dive site due to strong current or a long duration swim.
How long shall the command smooth log be maintained?
Three years IAW OPNAVINST 3150.27
Who approves operating and emergency procedures?
NAVSEA CODE 00C3 for sea and portable equipment.
NAVFAC CODE 00CE for shore facilities.
What are the normal and max working limits for SCUBA?
The normal working limit for SCUBA is 130 FSW and the max limit is 190 FSW.
What are the normal working limits for MK-21 and MK-20 UBA's?
The normal working limit for MK-20 is 60 FSW. The normal working limit for MK-21 using air is 190 FSW.
Describe the components of a MK-20 ESDS emergency gas supply for enclose space diving.
The ESDS system for MK-20 requires and adequately charged ANU approved SCUBA cylinder with a K or J valve. An approved SCUBA regulator set at the manufacturers recommended pressure but no lower than 135 PSI with an EGS whip 50-150 ft. long. If EGS is kept topside the first stage is set to 150 PSI. An approved pressure gauge attached to the first stage is also required.
Under what conditions may a pair of buddy divers have only one watch and depth gauge?
When diving SCUBA and a buddy line is used.
What are the requirements for using MK-20 in SCUBA mode?
It may be used with an approved single hose first stage regulator with an octopus to the approved max depth of the regulator as indicated in the ANU list.
When is a float line not authorized when tending a single SCUBA diver?
When direct access to the surface is not available.
What type of material is mandatory for SCUBA charging strain relief?
Cable, chain, twenty-one thread or 3/8" nylon line married at a minimum of every 18".
What size and material shall the marrying cord be?
The marrying cord shall be 1/8" nylon or material of equivalent strength.
When is EGS mandatory for MK-21 MOD 1?
Depths deeper than 60 FSW and diving inside a wreck.
When used in a free flow mode how much air is consumed by the MK-21 MOD 1.
What are the SCUBA diving restrictions for USN civilian divers?
SCUBA diving not to exceed 130FSW
No deeper than a 100 FSW without a recompression chamber on station.
What are the SCUBA equipment restrictions for USN civilian divers?
All SCUBA manifolds will be equipped with a J valve or an independent reserve cylinder with a seperate regulator
A submersible pressure gauge is required.
What are the SSD diving restrictions to USN civilian divers?
SSD will not be conducted greater than 190FSW
In-water decompression will be restricted to less than 120 minutes
What are the SSD equipment restrictions for USN civilian divers?
An EGS bottle is required deeper than 60FSW
EGS required for planned decompression dives
EGS required when direct access to the surface is not available.
What are the mixed gas diving restrictions for USN civilian divers?
Max depth of 220FSW
Less than 120 minute in-water decompression time
A chamber must be on station.
What are the recompression chamber restrictions for USN civilian divers?
An on-station chamber is defined as a certified and ready chamber on station.
A chamber shall be on station for all planned decompression dives or dives deeper than a 100'.
Civilian divers will remain at the chamber for one hour if making a dive that required a chamber on station.