Completed-Dive SAC & RMV Record. Reproduce pressure-basis SAC and cylinder-specific surface-volume RMV from one named completed segment, matching cylinder rating records, copied average ATA, and an independent RMV check.
Specialist tool for Scuba Diving1 documented formula8 real workflowsPrivate in your browser
Use this result well
A quick decision brief for this specific tool
Inputs that matter
One de-identified completed-segment scope and basis; explicit imperial or metric cylinder-rating system; named cylinder-rating, pressure/time segment, average ambient ATA and independent RMV records; start/end gauge pressure; matching rated free-gas capacity/rated pressure; elapsed minutes; copied average ATA; and same-unit independent RMV
Output to expect
Pressure used, cylinder constant, pressure-basis SAC, cylinder-specific surface-volume RMV, surface-equivalent gas used, observed ambient-volume rate and signed same-unit independent RMV difference
How it works
Subtract the completed gauge readings, divide by elapsed minutes and copied average ATA for pressure SAC, multiply by the matching rated-volume/rated-pressure cylinder constant for RMV, and subtract the independent RMV; do not convert depth silently or infer a future plan or human-performance verdict
Confirm the rating pair belongs to the exact cylinder and distinguishes rated free-gas capacity from water capacity, working pressure, test pressure and service pressure; review gauge accuracy, temperature, compressibility, gas mix and actual fill conditions separately.
Use this only as a retrospective segment record. Follow current training, operator procedures, responsible dive planning and qualified supervision for reserves, turn pressure, ascent/decompression, oxygen exposure, buddy gas, workload, future duration and all safety decisions.
Choose your path
Built around the job you need to finish
Reproduce pressure-basis SAC and cylinder-specific surface-volume RMV for one named completed segment without converting depth silently or prescribing reserves, future duration, physiology or dive safety.
Certified diver reconciling a completed log segment
Keep a retrospective pressure-consumption record separate from future gas planning and avoid confusing psi-per-minute SAC with surface-volume RMV.
Name the completed segment, cylinder rating pair and average-ATA source, copy the gauge/time values, and compare the reproduced RMV with an independent same-unit worksheet.
Can identify an arithmetic or record mismatch without receiving a reserve, turn-pressure, ascent or future-duration instruction.
Dive-team record reviewer checking cylinder basis
Verify that the selected free-gas capacity and rated pressure belong together and are not water capacity, test pressure or a different service-pressure mark.
Select imperial or metric basis, retain the exact cylinder source, inspect the cylinder constant and signed independent difference, then review temperature, gauge, gas and fill conditions externally.
Gets an auditable completed-record calculation while equipment acceptance and operational planning remain with responsible procedures and supervision.
Scuba trainee learning SAC versus RMV terminology
Understand why the same pressure SAC produces a cylinder-dependent volume rate and why average ATA cannot be inferred from maximum depth alone.
Run the imperial exercise, repeat it with a coherent metric rating pair, test mismatched independent records and invalid pressure ordering, and explain every unit transition.
Can distinguish pressure/minute SAC, cylinder constant and surface-volume/minute RMV without treating a number as fitness, stress or safety evidence.
Authoritative checks for this tool
Outputs and checklists are planning aids. Review the linked current authorities and the records, terms, instructions, and requirements that apply to your exact situation before a consequential decision.
NOAA expresses SAC as pressure per minute normalized by depth pressure. Copy a completed segment and its average ambient absolute pressure record; the worksheet does not infer ATA from maximum or average depth.
Pressure SAC = (start gauge pressure − end gauge pressure) ÷ elapsed minutes ÷ documented average ATA
Cylinder constant
Use one coherent manufacturer or responsible rating pair. Rated free-gas capacity is not internal water volume, and working, test and service-pressure markings are not automatically interchangeable.
RMV is a surface-volume rate tied to the entered rating basis. Compare only an independent value using scf/min for an imperial record or L/min for a metric record; a signed mismatch is a reconciliation cue, not safety approval.
A de-identified exercise records 3,000 to 1,800 psi over 30 minutes at a copied average 2.5 ATA with an 80 scf/3,000 psi rating pair. The worksheet reproduces 16 psi/min SAC and 0.426667 scf/min RMV, then compares an independent 0.43 scf/min record.
Select the metric rating record, enter bar with a matching rated free-gas capacity in liters, and keep the independent worksheet in L/min. Do not mix a cylinder's water capacity or test-pressure marking into the rating pair.
Change only the independent RMV to expose a signed mismatch, then review the named sources. The result cannot diagnose fitness, stress, buoyancy, breathing efficiency or the suitability of a future profile.
FAQ
No. In the NOAA formula set, SAC is a pressure-per-minute rate normalized by ambient pressure. Multiplying it by the exact cylinder constant produces a cylinder-specific surface-volume RMV in scf/min or L/min.
Depth-to-pressure conversion depends on water and surface-pressure context, and maximum depth does not represent the complete segment. Copy the reviewed average ambient absolute pressure in ATA from the responsible record instead of letting this worksheet assume a conversion.
Use rated free-gas capacity paired with its rated gauge pressure. Do not substitute internal water capacity, test pressure, service pressure or a capacity from another cylinder without responsible documentation.
No. A completed-segment rate can reflect many diver, task, equipment and environmental conditions. This worksheet provides arithmetic and a record comparison, not a physiological, skill, stress or safety assessment.
Not by itself. Reserves, turn pressure, ascent, decompression, oxygen exposure, buddy gas, failures and future conditions belong to current training, operator procedures, the responsible dive plan and qualified supervision.
About Completed-Dive SAC & RMV Record
Use this retrospective worksheet to reconcile one completed pressure-and-time segment. Keep pressure-basis SAC separate from cylinder-specific surface-volume RMV, copy the exact rated free-gas capacity/rated-pressure pair, and retain the source for average ambient absolute pressure. This record does not plan a future dive or evaluate a diver.
