clownfishsydney
Contributor
From http://www.divingmedicine.info/Ch 14 SM10c.pdf by Dr Carl Edmonds et al:
Following experiments and reviewing of the established decompression tables, between 1960 and 2000 a whole series of innovations and modifications were introduced. Dr Bruce Bassett (a USAF physiologist) concluded that the US Navy Tables resulted in an excessive incidence of about 6% DCS, when pushed to the no-decompression limits. Merrill Spencer in Seattle verified this observation and supported it with extensive Doppler monitoring, showing that bubbles developed in many routine dives – implying inadequate decompression. Many others observed similar inadequacies and in an attempt to cope with this new information, tables Chapter 14 — 2 based on modified Haldane principles were developed by Bassett, Huggins, NAUI, PADI, and many others. The main alterations to improve safety were in;
Following experiments and reviewing of the established decompression tables, between 1960 and 2000 a whole series of innovations and modifications were introduced. Dr Bruce Bassett (a USAF physiologist) concluded that the US Navy Tables resulted in an excessive incidence of about 6% DCS, when pushed to the no-decompression limits. Merrill Spencer in Seattle verified this observation and supported it with extensive Doppler monitoring, showing that bubbles developed in many routine dives – implying inadequate decompression. Many others observed similar inadequacies and in an attempt to cope with this new information, tables Chapter 14 — 2 based on modified Haldane principles were developed by Bassett, Huggins, NAUI, PADI, and many others. The main alterations to improve safety were in;
- reducing the acceptable no-decompression times by 10-20%
- reducing ascent rates from 18 m/min to 9-10 m/min (at least in the top 30m)
- Adding a “safety stop” of 3-5 min at 3-5 m.