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Dive Tables

Repetitive Dive. Surface Interval. Cold, Arduous Dive. Dive Computers. Dive Tables. Decompression Theory. Safety Stop. Residual Nitrogen. Bottom Time. No Decompression Limit. N. N. 2. N. 2. 2. N. 2. N. 2. N. 2. Nitrogen Absorption. Outgas. Final Level. Residual.

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Dive Tables

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  1. Repetitive Dive Surface Interval Cold, Arduous Dive Dive Computers Dive Tables DecompressionTheory Safety Stop Residual Nitrogen Bottom Time No Decompression Limit

  2. N N 2 N 2 2 N 2 N 2 N 2 Nitrogen Absorption Outgas Final Level Residual Surface Interval Dive 2 Dive 1 Additional Absorbed Absorbed Residual

  3. Revolving Charge Account Purchase Table Credit Rating 100 200 300 400 500 600 700 800 900 1000 A B C D E F G H I J 1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 1 2 3 4 5 6 7 8 1 2 3 4 5 6 7 1 2 3 4 5 6 1 2 3 4 5 1 2 3 4 1 2 3 1 2 1 Terms: Limit - $1,000 $100 Increments $100 Repay Inc Repay Weekly 0 100 200 300 400 500 600 700 800 900 A B C D E F G H I Outstanding Balance Repayment Table New Credit Rating

  4. 1837 first described after hard hat salvage operation (symptoms were attributed to cold water) Caisson workers in the late 1800’s 1900 Haldane commissioned by British Admirality to study and solve problem of DCS History of Decompression Sickness (DCS)

  5. Haldane conducted saturation experiments with animals Established a 2:1 pressure ratio (half times) Four factors involved in N2 absorption Pressure gradient Tissues absorb at different rate Blood flow is not equal to all parts of the body Tissue half times 5 - 10 - 20 - 40 - 60 Development of Dive Tables

  6. Deep dives Repetitive dives Multi-day diving Fatigue Dehydration Age Temperature Exertion Decompression diving Rapid ascent DCS Risk factors

  7. Dive Tables Dive Planning and Scheduling Tool Types of Dives • Depth • Time • Repetition No Decompression Repetitive Decompression No Stop Required on Ascent Mandatory Stop on Ascent

  8. Repet Dive SI 10 min - 12 hrs DCIEM Dive Tables Terminology End of Dive Repet Group (RG) Letter Surface Interval Time (SI) Before Dive Repet Factor (RF) ( : ) ( : ) Safety Stop 15’-25’ Safety Stop 15’-25’ Safety Stop 15’-25’ Depth NDL BT Dive 1 Dive 2 Dive 3 ABT ABT Actual bottom time ABT Residual Nitrogen Time (RNT) = No-D Limit(NDL) - Residual No-D Limit (RNDL) RNT = NDL - RNDL EBT = ABT + RNT Effective Bottom Time (EBT) = ABT + RNT • EBT Must Be Less Than or Equal to RNDL • The RG for each repetitive dive must be greater than that of the preceding dive • After 3 days of repetitive diving, a day off is recommended

  9. Dive 1 87 Feet for 17 Minutes Repetitive Group (RG) Letter D

  10. Surface Interval (SI) 2:00 D 1.3 Repetitive Factor (RF)

  11. Repetitive Dive Planning (SI)2:00 D 1.3 87’/17min 65 ft Repetitive No-D Limit RNDL = 21 Residual Nitrogen Time (RNT) RNT = NDL - RNDL = 35 - 21 = 14 min

  12. Repetitive Dive (SI)2:00 E D 1.3 87’/17min 65 ft ABT = 19 min Repetitive No-D Limit RNDL = 21 Residual Nitrogen Time (RNT) RNT = NDL - RNDL = 35 - 21 = 14 min Effective Bottom Time (EBT) EBT = ABT + RNT = 19 + 14 = 33 min

  13. Repetitive Factor (SI)2:00 (SI) 3:00 E D 1.3 1.3 87’/17min 65 ft ABT = 19 min

  14. Repetitive Dive Planning (SI)2:00 (SI) 3:00 E D 1.3 1.3 45 ft 87’/17min 65 ft ABT = 19 min Repetitive No-D Limit RNDL = 50 Residual Nitrogen Time (RNT) RNT = NDL - RNDL = 75 - 50 = 25 min

  15. Repetitive Dive (SI)2:00 (SI) 3:00 G E D 1.3 1.3 45 ft 87’/17min 65 ft ABT = 45 min ABT = 19 min Repetitive No-D Limit RNDL = 50 Residual Nitrogen Time (RNT) RNT = NDL - RNDL = 75 - 50 = 25 min Effective Bottom Time (EBT) EBT = ABT + RNT = 45 + 25 = 70 min

  16. The use of electronic dive computers to permit multi-level diving is permissible, but only if such instruments are used strictly according to the manufacturer’s instructions and recommendations and only for no-decompression diving. Computers should be monitored and the dive controlled in a manner that will permit a direct ascent to the surface at any time. Dive Computers

  17. Do not push tables/computer to limits Surface Intervals 1 hour minimum, longer is better Safe Dive Practices

  18. Slow Ascent Rates Ascent rates shall be controlled at 30 fsw/min from 60’ and not exceed 60 fsw/min from depth. Reference: Lang, M.A. and R.W. Hamilton (eds.). 1989. Proc. of the AAUS Dive Computer Workshop. USC Catalina Marine Science Center. USC Sea Grant Publ. USCSG-TR-01-89. 231 p. Lang, M.A. and G.H. Egstrom (eds.). 1990. Proc. of the AAUS Biomechanics of Safe Ascents Workshop. Woods Hole, MA. American Academy of Underwater Sciences Publ. AAUSDSP-BSA-01-90. 220p. Safe Dive Practices

  19. Safety Stops A stop in the 10-30 fsw zone for 3-5 minutes is required on every dive. Reference: Lang, M.A. and R.W. Hamilton (eds.). 1989. Proc. of the AAUS Dive Computer Workshop. USC Catalina Marine Science Center. USC Sea Grant Publ. USCSG-TR-01-89. 231 p. Lang, M.A. and G.H. Egstrom (eds.). 1990. Proc. of the AAUS Biomechanics of Safe Ascents Workshop. Woods Hole, MA. American Academy of Underwater Sciences Publ. AAUSDSP-BSA-01-90. 220p. Safe Dive Practices

  20. Divers should have a minimum surface interval of 12 hours before ascending to altitude. Flying after diving

  21. Summary Emergency Procedures Safety • Don’t “Push” Tables • S.A.F.E. Dive • Safety Stops • Deepest Dive First • Multi-Day, Multi-Dives • Cold, Arduous Dive • Flying After Diving • High Altitude Diving • NDL Inadvertently • Exceeded • Cease Diving • Observe for DCS • If DCS Symptoms appear • Administer 100% Oxygen • Evacuate Don’t Make The $30,000 Mistake

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