Principal Investigator: Craig Cooper, NURC/UNCW
Mission: April 21 — 25 2008
The NOAA Undersea Research Center (NURC) at the University of North Carolina Wilmington is working for the third straight year on a saturation project with the Navy’s Specialized Research Diving Detachment (SRDD) to conduct two Aquarius underwater laboratory saturation missions- utilizing Underwater Breathing Apparatus (UBA), or rebreathers, for aquanaut excursions.
Rebreathers were used in early Navy habitat saturation diving in the 60’s, and from NOAA saturation habitats in the 70’s, but since that time, excursion diving has been done almost exclusively on open circuit scuba. There is a continuing interest by the NOAA Undersea Research Program (NURP) in the use of rebreathers from Aquarius, and the Navy, because of their extensive background in using rebreathers, is the logical choice to demonstrate the feasibility related to rebreather maintenance in a saturation environment, and their use on working dives. Four missions were conducted in 2006 and two more in 2007 using Navy MK16 rebreathers to conduct work from Aquarius, all with successful results for rebreather performance and work accomplished by the divers.
NURC expects to further address the following rebreather performance and construction issues:
Maintenance of rebreathers by aquanauts during the mission, both planned pre- and post-dive servicing and checks, and unscheduled repairs;
Increased bottom times between “fills” over open circuit scuba;
The logistics of supplying consumables for rebreathers such as CO2 absorbent, O2, and diluent gases;
Installation of brackets and flask saddles associated with increasing the capacity of Aquarius' subsea HP air flask farm;
Drilling and grouting of bolts in the concrete base for fastening of new Southeast Crossroads Waystation;
Continued core drilling and grouting of seabed fasteners and base module for the fixed telemetry tower near Aquarius;
Disassembly, relocation, and setup of the Kamper Waystation to a new site 400' from Aquarius;
Possible use of the NURP developed REPEX tables, or modifications of the original tables developed for repetitive habitat excursions under NURP Technical Reports 88-1A & B.
Results from the previous six saturation missions with SRDD divers have shown the feasibility of using rebreathers from Aquarius, and the next step is to find an available commercial/recreational rebreather that performs as well as the Navy's MK 16 UBAs. A test and evaluation saturation mission with one that NURC has been using is now scheduled for May 2008, and NURC hopes to experience the same success thanks to the work with SRDD.