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PTRD DIVING CENTERS
June 24, 2017
September 8, 2020
Choose the correct option
Us Navy and NOAA Dive Tables define a _____ dive as any dive made less than 12 hours after surfacing from a prior dive.
What is the best choice of words when discussing dive tables and why?
Reliable; because even though all dive tables are based on hypothetical decompression models, reliable tables provide acceptable risk.
Best guess; because there is no theoretical basis for dive tables.
Individually specific; because modern decompression models allow the user to account for all of the factors influencing decompression risk.
Safe; because dive tables are based on proven physiological models reflecting how the human body absorbs and eliminates nitrogen.
Using US Navy or NOAA Air Dive Tables determine the adjusted maximum dive time for a repetitive dive with no decompression for a diver with a Group Designation Letter of D wanting to make a repetitive dive to 50\'.
Using US Navy or NOAA Air Dive Tables, determine the residual nitrogen time (RNT) for a diver with a Group Designation Letter of G wanting to make a repetitive five to 60\'.
Unlike Dive Tables, Dive Computers calculate a dive profile in \"real time\"; compute \"multilevel dives\"; and have automatic dive log functions.
A diver realizes he has exceeded his planned dive schedule and does not have contingency tables. The diver can:
Surface and breath oxygen for a minimum of 60 minutes.
Surface and, if asymptomatic, return to the water within five minutes to the depth of the missed decompression and remain for one and one-half times the required stop time.
None of the above.
All of the above.
Ascend at a proper rate and stop at 10 to 15 fsw for a minimum of 15 minutes or until cylinder pressure reaches 300 psi. If the time spent at 10 to 15 ' did not equal or exceed the required decompression time, the diver should be placed on oxygen for a minimum of 30 minutes, observed, and restricted from diving for 12 hours.
Using US Navy or NOAA Air Dive Tables, a dive to 70 feet (22m) for 31 minutes results in a Group Designation Letter of:
A diver using US Navy or NOAA Air Dive Tables plans a dive to 100\\\' for 25 minutes. The diver should calculate contingency dive plans accounting for exceeding both depth and time. Exceeding the planned depth by as little as a foot results in a five plan of:
110' for 30 minutes, requires a decompression stop at 10' for 7 minutes.
100' for 25 minutes requires no decompression stop.
110' for 25 minutes, requires a decompression stop at 10' for 3 minutes.
100' for 40 minutes, requires a decompression stop at 15' for 10 minutes.
______ stops are recommended while ______ stops are required by the dive tables.
Safety / omitted
Decompression / safety
Safety / decompression
Precautionary / scheduled
Unlike Dive Tables, Dive Computers and PC Based Decompression Software offer a method of calculating decompression obligation with zero risk of DCS.
Using US Navy or NOAA Air Dive Tables, a dive to 71 feet for 15 minutes followed by a one hour surface interval will result in a Group Designation Letter of:
Using US Navy or NOAA Air Dive Tables, a dive to 55 feet for 40 minutes followed by a 90 minute surface interval and a repetitive dive to 63 feet for 20 minutes will result in a Group Designation Letter of:
Even though this presentation does not address required decompression dive procedures in detail, divers using US Navy or NOAA Dive Tables are expected to know how to calculate required decompression schedules for contingency planning purposes.
US Navy and NOAA Dive Tables define a single dive as:
any dive made less than 12 hours after surfacing from a prior dive.
any dive made more than 24 hours following a previous dive.
any dive made less than 24 hours after surfacing from a prior dive.
any dive made more than 12 hours following a previous dive.
What is the significance of a Group Designation Letter with US Navy or NOAA Dive Tables?
It represents the amount of nitrogen a diver absorbs during a no-decompression dive. Once a diver reaches the no-decompression limit the diver becomes saturated with nitrogen and Group Designation Letters are no longer used.
It represents the amount of nitrogen a diver off-gases during a dive.
It represents the amount of nitrogen a diver absorbs during a dive to a given depth for a given period of time.
It represents the no-decompression limit for a given depth for a given period of time.
Time is Up!
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