surface supplied air tender’s course & u.s. navy tables

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Surface Supplied Air Surface Supplied Air Tender’s Course & U.S. Tender’s Course & U.S. Navy Tables Navy Tables Presented By: Presented By: The Riverside County The Riverside County Sheriff’s Underwater Search Sheriff’s Underwater Search and Recovery Team and Recovery Team

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Surface Supplied Air Tender’s Course & U.S. Navy Tables. Presented By: The Riverside County Sheriff’s Underwater Search and Recovery Team. Surface Supplied Air (SSA) Diving-Tender. Responsibilities: Help Divers Suiting Up Maintaining SSA Equipment Gas Management Field Neuro Exams - PowerPoint PPT Presentation

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Page 1: Surface Supplied Air Tender’s Course & U.S. Navy Tables

Surface Supplied Air Surface Supplied Air Tender’s Course & U.S. Tender’s Course & U.S.

Navy TablesNavy Tables

Presented By:Presented By:The Riverside County Sheriff’s The Riverside County Sheriff’s

Underwater Search and Recovery Underwater Search and Recovery TeamTeam

Page 2: Surface Supplied Air Tender’s Course & U.S. Navy Tables

Surface Supplied Air (SSA) Diving-TenderSurface Supplied Air (SSA) Diving-Tender• Responsibilities:Responsibilities:

– Help Divers Suiting UpHelp Divers Suiting Up– Maintaining SSA EquipmentMaintaining SSA Equipment– Gas ManagementGas Management– Field Neuro ExamsField Neuro Exams– CommunicationsCommunications– Timekeeping and TablesTimekeeping and Tables– Assisting with RescuesAssisting with Rescues

• Have more responsibilities than divers because they are responsible for divers.

Page 3: Surface Supplied Air Tender’s Course & U.S. Navy Tables

Predive Environmental ChecklistPredive Environmental Checklist

• Know the dive depthsKnow the dive depths• Dive AltitudeDive Altitude• Water temperatureWater temperature• Underwater visibilityUnderwater visibility• Bottom typeBottom type• HazardsHazards

Page 4: Surface Supplied Air Tender’s Course & U.S. Navy Tables

Personnel to Run SSA Dive OperationsPersonnel to Run SSA Dive Operations

• DiverDiver• TenderTender• Dive Supervisor*Dive Supervisor*• Standby DiverStandby Diver• Standby TenderStandby Tender• Timekeeper/Board OperatorTimekeeper/Board Operator• Boat Operator*Boat Operator*

Page 5: Surface Supplied Air Tender’s Course & U.S. Navy Tables

Tender-Prior to WaterTender-Prior to Water

• Checks the diver’s EquipmentChecks the diver’s Equipment– DrysuitDrysuit– HarnessHarness– Bailout systemBailout system– Manifold blockManifold block– WeightingWeighting– Air checkAir check– AGAAGA– CommunicationCommunication

Page 6: Surface Supplied Air Tender’s Course & U.S. Navy Tables

Tender-Prior to WaterTender-Prior to Water

• Checks air supply (bank)Checks air supply (bank)• NuerosNueros• Maintains contact with the diver once he is Maintains contact with the diver once he is

dresseddressed• Helps diver to entry pointHelps diver to entry point

Page 7: Surface Supplied Air Tender’s Course & U.S. Navy Tables

Tender-In the WaterTender-In the Water

• Communication CheckCommunication Check• Takes care of diver’s umbilical Takes care of diver’s umbilical • CommunicationsCommunications• Assists board operator with times and Assists board operator with times and

depth informationdepth information• Can rotate between jobs, but only after Can rotate between jobs, but only after

his/her diver is out of the waterhis/her diver is out of the water

Page 8: Surface Supplied Air Tender’s Course & U.S. Navy Tables

EmergenciesEmergencies

• FoulingFouling• Blow upBlow up• Loss of primary air supplyLoss of primary air supply• Loss of communications or contactLoss of communications or contact

Page 9: Surface Supplied Air Tender’s Course & U.S. Navy Tables

Postdive ProceduresPostdive Procedures

• HelpHelp diver out of equipment diver out of equipment• Stow umbilicalsStow umbilicals• Field NeurosField Neuros• Post dive maintenancePost dive maintenance on equipmenton equipment

Page 10: Surface Supplied Air Tender’s Course & U.S. Navy Tables

Timekeeper/Board operatorTimekeeper/Board operator

• Keeps accurate records of dive timesKeeps accurate records of dive times• DepthsDepths• Notes all important details of diveNotes all important details of dive• Monitors rates of flowMonitors rates of flow• Cannot change job until ALL divers are out Cannot change job until ALL divers are out

of water.of water.

Page 11: Surface Supplied Air Tender’s Course & U.S. Navy Tables

Supply Pressure Requirements-Demand Supply Pressure Requirements-Demand SystemSystem• Helps eliminate low levels of CO2 Helps eliminate low levels of CO2 • Basic Formula for determining require air Basic Formula for determining require air

pressures:pressures:– (depth in fsw X .445) + Manufacturer’s (depth in fsw X .445) + Manufacturer’s

recommendation over ambient pressure recommendation over ambient pressure setting= minimum supply pressure.setting= minimum supply pressure.

– ExampleExample:: [(130 fsw X .445) + 135 psig][(130 fsw X .445) + 135 psig]

(57 psi + 135 psig) = 192. 2 psig(57 psi + 135 psig) = 192. 2 psig This is the amount needed for the diver to This is the amount needed for the diver to

breathe easily at depth.breathe easily at depth.

Page 12: Surface Supplied Air Tender’s Course & U.S. Navy Tables

U.S. Navy TablesU.S. Navy Tables• What Are Dive Tables?What Are Dive Tables?

– They are a are printed cards or booklets that They are a are printed cards or booklets that allow divers to determine for a particular dive allow divers to determine for a particular dive profile and breathing gas, the decompression profile and breathing gas, the decompression stops required for that dive in order to avoid stops required for that dive in order to avoid decompression sickness. decompression sickness.

– In actuality, they are a “theoretical” model or In actuality, they are a “theoretical” model or limit of a decompression procedure that does limit of a decompression procedure that does not establish a hard line between developing or not establish a hard line between developing or not developing decompression sickness. not developing decompression sickness.

– Basically, using these tables establishes an Basically, using these tables establishes an “acceptable risk” and you can still get bent using “acceptable risk” and you can still get bent using them.them.

Page 13: Surface Supplied Air Tender’s Course & U.S. Navy Tables

Dive PlanningDive Planning• Single Vs. Repetitive DiveSingle Vs. Repetitive Dive

– Single dive: A dive made within more Single dive: A dive made within more than 12 hours following a previous dive.than 12 hours following a previous dive.

– Repetitive dive: A dive made less than 12 Repetitive dive: A dive made less than 12 hours after surfacing from a prior dive.hours after surfacing from a prior dive.

• Planning a single dive-Definitions:Planning a single dive-Definitions:– Know Actual Bottom time (ABT)Know Actual Bottom time (ABT)– Know No Decompression Limits (NDL)Know No Decompression Limits (NDL)– Know DepthKnow Depth– Know Dive ScheduleKnow Dive Schedule

Page 14: Surface Supplied Air Tender’s Course & U.S. Navy Tables

Dive PlanningDive Planning• ABT starts when the diver leaves the ABT starts when the diver leaves the

surface and ends when the diver begins a surface and ends when the diver begins a direct, uninterrupted ascent to the surface.direct, uninterrupted ascent to the surface.

• No Decompression limit is the maximum No Decompression limit is the maximum time a diver can stay at a given depth.time a diver can stay at a given depth.

• Depth is defined as the maximum depth Depth is defined as the maximum depth reached during any point of the dive—reached during any point of the dive—even if the diver is there momentarily.even if the diver is there momentarily.

• ““Dive Schedule” refers to the combination Dive Schedule” refers to the combination of ABT and Depth as they appear on the of ABT and Depth as they appear on the table.table.

Page 15: Surface Supplied Air Tender’s Course & U.S. Navy Tables

Dive PlanningDive PlanningStart of Descent

Actual Bottom Time

Dive Profile

Maximum Depth

Start of Ascent

Page 16: Surface Supplied Air Tender’s Course & U.S. Navy Tables

NDLNDL• No Decompression No Decompression

LimitsLimits• Left side of the tableLeft side of the table• What is the NDL for What is the NDL for

60 feet?60 feet?• What is the NDL for What is the NDL for

100 feet100 feet• What is the NDL for What is the NDL for

140140

Page 17: Surface Supplied Air Tender’s Course & U.S. Navy Tables

Question?Question?• Can a team make a dive to 80 feet Can a team make a dive to 80 feet

for 45 minutes?for 45 minutes?– No. The NDL is 39 minutesNo. The NDL is 39 minutes

Page 18: Surface Supplied Air Tender’s Course & U.S. Navy Tables

Repetitive DivesRepetitive Dives• More complex than single dive planning.More complex than single dive planning.• Need to remember two things:Need to remember two things:

– A simple written means of recording all A simple written means of recording all information pertaining to the dives that information pertaining to the dives that were made.were made.

– Need dive table information that accounts Need dive table information that accounts for the residual nitrogen (RNT) present from for the residual nitrogen (RNT) present from previous divesprevious dives

Page 19: Surface Supplied Air Tender’s Course & U.S. Navy Tables

Recording Repetitive DivesRecording Repetitive DivesStart of Descent

ABTStart of Ascent

/

Schedule Used

End of ascent/start of surface interval

Start of descent/end of surface interval

Surface Interval Time (SIT)

Repetitive letter group

RNT+ABTESDT

Depth

Time

Page 20: Surface Supplied Air Tender’s Course & U.S. Navy Tables

Accounting For Residual Accounting For Residual NitrogenNitrogen• Table 9-7 Repetitive Group Table 9-7 Repetitive Group

DesignationDesignation• Table 9-8 Combination of two tables.Table 9-8 Combination of two tables.

– Upper table depicts how the surface Upper table depicts how the surface interval reduces excess nitrogeninterval reduces excess nitrogen

– Lower table shows how divers must Lower table shows how divers must account for this excess nitrogen on account for this excess nitrogen on subsequent dives.subsequent dives.

Page 21: Surface Supplied Air Tender’s Course & U.S. Navy Tables

Dive PlanningDive Planning• After a single dive of 47 feet with an After a single dive of 47 feet with an

actual bottom time of 39 minutes actual bottom time of 39 minutes answer the following questions:answer the following questions:– What is the Schedule used?What is the Schedule used?

•50’ / :4150’ / :41– What is the repetitive group designation What is the repetitive group designation

at the end of the dive?at the end of the dive?•FF

Page 22: Surface Supplied Air Tender’s Course & U.S. Navy Tables

Repetitive Group After Surface Repetitive Group After Surface IntervalInterval• The longer the diver remains on the surface The longer the diver remains on the surface

after a dive, the less residual nitrogen after a dive, the less residual nitrogen (RNT) will be present in the diver’s tissues.(RNT) will be present in the diver’s tissues.

• The surface interval must be accounted for The surface interval must be accounted for and a “new” Repetitive Group Designator and a “new” Repetitive Group Designator must be assignedmust be assigned

• This “new” designator affects how long a This “new” designator affects how long a diver can remain underwater on repetitive diver can remain underwater on repetitive dives, without exceeding the NDLs.dives, without exceeding the NDLs.

Page 23: Surface Supplied Air Tender’s Course & U.S. Navy Tables

Repetitive Group After Surface Repetitive Group After Surface IntervalInterval• Determine the surface interval time (SIT).Determine the surface interval time (SIT).

– The surface interval is the time from the diver The surface interval is the time from the diver surfaces, spends sitting on the surface, and to surfaces, spends sitting on the surface, and to their next descent.their next descent.

• After the SIT, find the “new” Group After the SIT, find the “new” Group DesignatorDesignator– This is found on table 9-8. Start with the This is found on table 9-8. Start with the

last designator, find the time from last designator, find the time from surface to descent (or planned descent) surface to descent (or planned descent) and follow down to new designator.and follow down to new designator.

Page 24: Surface Supplied Air Tender’s Course & U.S. Navy Tables

Dive PlanningDive Planning• Starting with the last dive, our Starting with the last dive, our

ending Repetitive Group Designator ending Repetitive Group Designator was F. What is the “new” designator was F. What is the “new” designator after a 4:04 SIT?after a 4:04 SIT?– BB

Page 25: Surface Supplied Air Tender’s Course & U.S. Navy Tables

Determining Adjusted NDLDetermining Adjusted NDL• Accounting for Nitrogen in the diver’s tissues Accounting for Nitrogen in the diver’s tissues

from previous dives.from previous dives.• The RNT must be added into all subsequent The RNT must be added into all subsequent

repetitive dives. repetitive dives. • To determine the Adjusted NDL, subtract the To determine the Adjusted NDL, subtract the

RNT from the NDL of the next dive able RNT from the NDL of the next dive able depth.depth.

• The RNT + ABT = Equivalent Single Dive The RNT + ABT = Equivalent Single Dive Time (ESDT)Time (ESDT)

• The ESDT is the factor used to determine dive The ESDT is the factor used to determine dive schedules for all subsequent repetitive dives. schedules for all subsequent repetitive dives.

Page 26: Surface Supplied Air Tender’s Course & U.S. Navy Tables

Dive PlanningDive Planning• Continuing with the previous dive, find Continuing with the previous dive, find

the following with a dive to 46’ for :22:the following with a dive to 46’ for :22:– What is the RNTWhat is the RNT– What is the Adjusted NDLWhat is the Adjusted NDL– What is the ESDTWhat is the ESDT– What is the dive scheduleWhat is the dive schedule– What is the “new” repetitive group What is the “new” repetitive group

designator?designator?

Page 27: Surface Supplied Air Tender’s Course & U.S. Navy Tables

Dive PlanningDive Planning• What is the RNTWhat is the RNT

– 1717• What is the Adjusted NDLWhat is the Adjusted NDL

– 7575• What is the ESDTWhat is the ESDT

– 3939• What is the dive scheduleWhat is the dive schedule

– 50/4150/41• What is the “new” repetitive group?What is the “new” repetitive group?

– FF

Page 28: Surface Supplied Air Tender’s Course & U.S. Navy Tables

Sample ProblemsSample Problems

Page 29: Surface Supplied Air Tender’s Course & U.S. Navy Tables

Determining the minimum Determining the minimum surface intervalsurface interval• Must know the ESDT for the second dive. The ESDT Must know the ESDT for the second dive. The ESDT

will be the same as the NDL for the second dives will be the same as the NDL for the second dives max depthmax depth

• Deduct the team’s max planned ABT from the max Deduct the team’s max planned ABT from the max ESDT. This will reveal the RNT.ESDT. This will reveal the RNT.

• Consult the bottom of table 9-8 for your depth. Go Consult the bottom of table 9-8 for your depth. Go across that depth until you find your RNT or that across that depth until you find your RNT or that close to it.close to it.

• Follow it up until you find the Repetitive Group. Follow it up until you find the Repetitive Group. From the first dive’s Group Designation to where From the first dive’s Group Designation to where the Repetitive Group intersects is the minimum the Repetitive Group intersects is the minimum surface intervalsurface interval

Page 30: Surface Supplied Air Tender’s Course & U.S. Navy Tables

Sample ProblemsSample Problems

Page 31: Surface Supplied Air Tender’s Course & U.S. Navy Tables

Dealing with AltitudeDealing with Altitude• Any dive over 1000 feet in altitude is Any dive over 1000 feet in altitude is

considered an altitude dive.considered an altitude dive.• All altitude dives need special tablesAll altitude dives need special tables• Traveling after an altitude diveTraveling after an altitude dive• Changes in gauges. Changes in gauges.

Page 32: Surface Supplied Air Tender’s Course & U.S. Navy Tables

Ready for the Test?Ready for the Test?Need:Need:

Scratch paperScratch paperCalculatorCalculator

PencilPencil