Repetitive/Multi-Level Dive Procedures and Tables for Constant 0.7 ATA Oxygen Partial Pressure in Nitrogen Diving.

Abstract : The U.S. Navy Experimental Diving Unit (NEDU) has previously developed and tested a computer algorithm for computing real time decompression schedules for a constant 0.7 ATA PO2 in N2 breathing medium. This algorithm was developed primarily for use with the MK 15 or MK 16 closed circuit underwater breathing apparatus (UBA), but can be used with any closed circuit UBA which uses a nitrogen or nitrogen-oxygen diluent and which maintains the inspired oxygen tension at 0.7 ATA or greater. The computer algorithm which resulted from manned testing is known as the EL-MK 15/16 Real Time Algorithm (EL-MK 15/16 RTA) and is intended to be programmed into a small portable underwater decompression computer (UDC) which is carried by the diver and which updates the decompression profile in real time every 2 seconds. The same decompression model used to develop the EL-MK 15/16 RTA was also used to compute a set of decompression tables for use when a UDC is unavailable. Both the EL-MK 15/16 RTA and the resultant decompression tables are already in Fleet use. During development of the EL-MK 15/16 RTA, multiple level and repetitive dive profiles were tested. This report describes the assumptions used in developing these repetitive dive tables and also presents a full set of tables with instructions for their use.