mputers

: 5

t i n Dive Tables Air Equivalent Depth and Standard Air Tables Using NAUI’s RGBM Tables The Rule of Halves Dive Computers • • • • •

U Dive Tables and Dive Co Dive and Tables Dive

Unit 5 - Dive Tables and Dive Computers Dive X : e c n a m r diving. X o f r e P t n e d

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Tables. how it is Depth and Equivalent Air Define Dive Tables. used with Air how to determine and calculate Demonstrate Depth. Equivalent Air the use of the NAUI RGBM Demonstrate Dive Tables. use it of Halves” and how to State the “Rule diving. in all of your procedures for using dive Describe the EAN computers for Demonstrate the use of NAUI EAN the use Demonstrate t • • • • • •

will be able to: will be you the lesson end of By the S

Unit 5 - Dive Tables and Dive Computers

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b NAUI Dive Tables NAUI Dive Tables NAUI RGBM Tables U.S. Navy DCIEM Tables Buhlmann Other Tables v h a i – – – – – – t

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Unit 5 - Dive Tables and Dive Computers s e l b a T e v i

D called “standard dive tables” are tables” “standard dive called -

r i So air. while for diving designed

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Unit 5 - Dive Tables and Dive Computers s e m i T p o t S d e r i u q e r

- o EANx Dive Tables give increased give increased Dive Tables EANx mixes. for standard dive times maximum

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Unit 5 - Dive Tables and Dive Computers e s v i e l D b

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Unit 5 - Dive Tables and Dive Computers e v i level atmospheric - D x o r t i N r i A d continued e

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, and adjustments must be made for altitudes above must be made for altitudes pressure, and adjustments meters. about 1000 feet/300 to altitude after diving, wait 12 hours If flying or ascending and 18 hours after a repetitive dive series. after a single dive Treat each dive as a square profile dive, with the deepest point profile dive, with dive as a square Treat each the whole as the depth for the dive being used reached on dive. the table, round not appear on depth or time does If the exact number. up to the next greater an ascent rate of 30 feet/9 meters per The tables assume minute. dives progressively shallower will yield Planning repetitive interval times. shorter required surface is 10 interval between two separate dives The required surface one recommended surface interval is minutes; the minimum hour. to be used at sea The tables are designed r b – – – – – – – n NAUI EAN Dive Table Rules NAUI EAN

a T

• E

Unit 5 - Dive Tables and Dive Computers Tables Air Depth and and Depth Air

It is not the actual depth, but the It is not the actual of in the partial pressure matters. that Because nitrox has a lower fraction Because nitrox has air, the nitrogen of nitrogen than will also be less than partial pressure depth, and the with air for any given depth for nitrogen diver’s equivalent be less than with absorption will also air. – –

Equivalent Air Depth is Air Depth Equivalent by the partial determined that of nitrogen pressure is actually breathing Standard Air Air Standard Equivalent Equivalent •

Unit 5 - Dive Tables and Dive Computers continued r Depth and and r Depth Tables Tables

If you were breathing a mixture that is 36% a mixture that breathing If you were would be percentage then the nitrogen , fraction would be 0.64. 64%, and the nitrogen with this mixture, you expose When you dive the nitrogen partial yourself to 64/79ths you would encounter if breathing pressure that air. be can consider your depth to Therefore, you 80%) of the absolute 64/79ths (roughly you would encounter at your pressure that you were breathing air. actual depth if – – – EAD Example:

Standard Air Air Standard Equivalent Ai Equivalent •

Unit 5 - Dive Tables and Dive Computers continued r Depth and and r Depth Tables Tables

Equivalent Air Depth by Table (imperial) by Table Air Depth Equivalent •

Standard Air Air Standard Equivalent Ai Equivalent

Unit 5 - Dive Tables and Dive Computers continued r Depth and and r Depth Tables Tables

Equivalent Air Depth by Table (metric) by Table Air Depth Equivalent

Standard Air Air Standard Equivalent Ai Equivalent •

Unit 5 - Dive Tables and Dive Computers continued equivalent absolute equivalent absolute - r Depth and and r Depth Tables Tables

Equivalent air depth can be calculated in can be calculated air depth Equivalent be procedure can steps, or the discrete a single formula. combined into at the absolute pressure Step 1: Determine you will be diving. the depth to which the nitrogen “credit” that your Step 2: Apply you. nitrox blend gives this air Step 3: Convert equivalent air depth pressure to an • • • •

Calculating Equivalent Air Depth Air Equivalent Calculating

Standard Air Air Standard Equivalent Ai Equivalent •

Unit 5 - Dive Tables and Dive Computers fsw/atm atm ata ) x 33 continued ) + 1 atm ) x P 1 – in air fsw/atm / F r Depth and and r Depth Tables EAD ata in mix = (F = (D fsw / 33 = (D fsw EAD

ata ata Step 1: P Step 2: P Step 3: EAD fsw = (P

Standard Air Air Standard Equivalent Ai Equivalent • • • • • •

Unit 5 - Dive Tables and Dive Computers ata to a fsw 32 continued r Depth and and r Depth Tables Tables

Example: What is the equivalent air the equivalent What is Example: diving with EAN depth for a diver depth of 80 feet/24 meters? depth of 80 –

Calculating EAD Calculating Step 1: Find the absolute pressure at 80 the absolute pressure at Step 1: Find = 3.42 from Chapter 2: or using the formula •

Equivalent Ai Equivalent Standard Air Air Standard

Unit 5 - Dive Tables and Dive Computers ata = 2.94 ata continued , the nitrogen , the nitrogen 32 equivalent absolute equivalent absolute - r Depth and and r Depth Tables Tables 0.32). Your air -

(air equiv) = (0.68/0.79) x 3.42 (air equiv) = (0.68/0.79)

ata pressure is set by the ratio between the by the ratio between the pressure is set in your mix and the fraction of nitrogen in air, or: fraction of nitrogen Step 2: Apply your nitrogen “credit.” Since nitrogen “credit.” Apply your Step 2: with EAN you are diving mix is 0.68 fraction of your (= 1.0 P –

Calculating EAD Calculating Equivalent Ai Equivalent Air Standard •

Unit 5 - Dive Tables and Dive Computers atm atm continued to an ) x 33 fsw / ) x 33 fsw / ata atm 1 atm – 1 r Depth and and r Depth Tables Tables – ata ata fsw

Step 3: Convert 2.94 Convert 2.94 Step 3: depth: equivalent air D fsw = (P D fsw = (2.94 = 64 on for 70 feet / 21 meters You would use your dive tables. – – – –

Calculating EAD Calculating •

Standard Air Air Standard Equivalent Ai Equivalent

Unit 5 - Dive Tables and Dive Computers ) 2 2 ( continued ) ) 0.79 0.79 r Depth and and r Depth Tables Tables x FN D fsw + 33 fsw ( w + 1 - FO D fsw + 33 fs æö ç÷ èø ( æö ç÷ èø

Calculating EAD using a single formula a single EAD using Calculating - 33 fsw EAD fsw = - 33 fsw EAD fsw =

Standard Air Air Standard Equivalent Ai Equivalent •

Unit 5 - Dive Tables and Dive Computers continued r Depth and and r Depth Tables Tables in the OCEANx -

To find equivalent air equivalent air To find

calculator, dial into the oxygen percentage The long upper window. below window immediately actual shows the maximum with each depth to be used depth, which equivalent air to is printed immediately the right. depth with the depth with the – Calculating EAD with the EAD with Calculating OCEANx

Standard Air Air Standard Equivalent Ai Equivalent •

Unit 5 - Dive Tables and Dive Computers - as well 36 level tables - ’s RGBM Tables RGBM ’s and EAN 32 planning information for planning information - as for air diving. The sea as for air diving. The altitudes up to 2000 feet/610 meters. altitudes up to 2000 tables are available Additional sets of between 2000 for diving at altitudes 1829 meters and and 6000 feet/610 to feet/1829 to 3048 for 6000 and 10,000 meters. provide dive Calculation” tables and do not require tables and do not Calculation” interval groups, a surface use of letter or residual nitrogen credit table, dive making repetitive times, thus easy and planning extremely straightforward. have been NAUI RGBM Dive Tables prepared for EAN NAUI RGBM Dive Tables are “No Dive Tables are NAUI RGBM • • Using NAUI Using •

Unit 5 - Dive Tables and Dive Computers s e l b a T

M B G dive depth. R - s ’ I U A N g n

A minimum surface interval of one hour is of one surface interval A minimum dive. between each required up depth is not listed, round If the actual dive depth. to the next greater no repetitive dive must be The depth of each depth shown on the row greater than the the right of the previous dive’s immediately to this it may be shallower than depth; of course, maximum repetitive i – – – s The important RGBM table rules are: RGBM The important • continued U

Unit 5 - Dive Tables and Dive Computers s e l b a T

M B G minute safety stop at 15 minute safety - R s ’ I U A N g n All dives require a 3 All dives require

feet (± 3 feet)/5 meters (± 1 meter) feet (± 3 feet)/5 As the tables are designed, there can be no there can tables are designed, As the dive. by a deeper dive followed shallow ascent rate is 30 feet/9 meters The maximum per minute. i – – – s The important RGBM table rules are: RGBM The important continued

• U

Unit 5 - Dive Tables and Dive Computers - hour - M Tables Tables M

period. In actual practice, the “third dive” may practice, the “third dive” period. In actual repetitive dives not exceeding be a series of dive time of 150 minutes. the total maximum 12 diving rule is to wait at least The flying after dive within the prior 18 hours after a single 18 hours after two dives, and hour period, 15 dives. hours after three On the sea level to 2,000 feet tables, no more feet tables, sea level to 2,000 On the 12 dives within a repetitive than three ing NAUI’s RGB NAUI’s ing – –

The important RGBM table rules are: RGBM The important • continued Us

Unit 5 - Dive Tables and Dive Computers s e l b a T

M B G R s ’ I U A N g n 1 hr Surface Interval 1 hr Surface

Dive 1: 24 m/80 feet for 47 minutes 24 m/80 feet Dive 1: Interval 1hour Surface feet for 85 minutes Dive 2: 18 m/60 feet for up 150 minutes Dive 3: 12 m/40 i – – – – – s Dive example (using EAN32) (using Dive example • continued U

Unit 5 - Dive Tables and Dive Computers bles Table on Dive Table on Dive 36 AUI’s RGBM Ta RGBM AUI’s

and use the RGBM EAN and use the RGBM 36

Two. For example, it is possible to use air and the NAUI is possible to use air and For example, it to on Dive One, then switch RGBM Air Table EAN When using the NAUI RGBM Tables, you may RGBM Tables, the NAUI When using oxygen leaner to richer tables from also switch to (or dive two to dive two from dive one fractions simply following the maximum dive three) by as you move between the depth constraints tables. appropriate dive Using N Using • • continued

Unit 5 - Dive Tables and Dive Computers minute safety stop minute safety - dive dive decompression - minute safety stop. Then minute safety -

When ending any no ending any When halve the / 40 feet, of 12 meters in excess depth to dive’s deepest from the distance Ascend to that depth and the surface. make a one ascent to the 5 meter/15 continue your two and complete the last foot safety stop three minutes of your feet. at 5 meters/15

• Rule of Halves of Rule

Unit 5 - Dive Tables and Dive Computers x o r t i N d n a s r e t u p m o profile” assumptions of dive tables. profile” assumptions - C

e

v i Dive computers perform real time dive calculations. real time dive perform Dive computers are quite conservative. their algorithms Generally, and dive time diver’s depth they sample the Because and recalculate nitrogen every few seconds a range of theoretical tissue absorption over divers enjoy extended dive times compartments, computer. when using a dive receives “credit” for the shallow In effect, the diver the dive, which is not possible with portions of the “square

• • • • D

Unit 5 - Dive Tables and Dive Computers x o r t i N d n a s r e t u p m o C e

Use a Nitrox capable computer Nitrox capable Use a computer to Use an Air capable safety margins. increase your v – –

i incorporated the NAUI RGBM algorithms as well NAUI RGBM algorithms incorporated the of Halves into their dive as the NAUI Rule computers. Two basic options Two basic Note: Currently, many manufacturers have many manufacturers have Note: Currently, • continued D

Unit 5 - Dive Tables and Dive Computers puters Dive Tables Air Equivalent Depth and Standard Air Tables Using NAUI’s RGBM Tables The Rule of Halves Dive Computers Dive Tables and Dive Com Dive Tables and Dive • • • • • End of Unit 5 of Unit End

Unit 5 - Dive Tables and Dive Computers : e c n a m r diving. x o f r e P t n e

d

u

Demonstrate the use of NAUI EANx Dive of NAUI EANx the use Demonstrate Tables. how it is Depth and Equivalent Air Define Dive Tables. used with Air how to determine and calculate Demonstrate Depth. Equivalent Air the use of the NAUI RGBM Demonstrate Nitrox Dive Tables. use it of Halves” and how to State the “Rule diving. in all of your procedures for using dive Describe the EAN computers for t • • • • • •

will be able to: will be you the lesson end of By the S

Unit 5 - Dive Tables and Dive Computers