Findings for sub-saturation diving exposures:

1. There is a national need for scientific divers to perform research at depths beyond the 190 fsw compressor air scuba limit.
2. CCRs and open-circuit trimix are currently being used in the scientific community.
3. Properly controlled mixed gas surface-supplied diving offers a reduced-risk method to conduct such dives.
4. Some marine science objectives may not be met by surface-supplied diving.
5. Surface-supplied/supported CCRs and SCRs warrant further consideration.
6. Scientific diving beyond 190 fsw will require increased funding allocations.
7. There are increased DCS risks associated with deep mixed gas dives.
8. Mixed gas diving requires adequate thermal protection.

Recommendations:

1. A phased program using existing assets should be initiated, starting with training exposure of scientists to standard air surface-supplied diving.
2. Appropriate operational and emergency response methods, including consideration of on-site chamber availability, need to be incorporated to mitigate the increased DCS risks.
3. Existing military and commercial decompression procedures are acceptable; consideration should be given to the development of new decompression procedures to better fit the scientific diving mission.
4. Mixed gas diver selection, training and proficiency requirements are necessarily more stringent than for air diving.