Evaluation of Sherwood SCUBA Regulators for Use in Cold Water

NEDU tested the breathing effort and susceptibility to freeze-up of two models of Sherwood SCUBA regulators, the Blizzard and the Maximus. Both regulators were teated in -2 deg C 28 deg F salt water, at depths to 6O.7 msw 198 fsw. Five examples of each model were tested. The probability of regulator failure was computed from the number of cold induced incidents, and the time to failure for each incident. Under these rigorous conditions, the probability of failure for the Sherwood Blizzard was approximately half that of the Maximus. Furthermore, the Blizzards breathing effort was consistently lower than the Maximus, especially at low supply pressures. The Sherwood Blizzard should be adequate for dives of up to 40 min duration in sea water temperature to 28 deg F. Deeper than 100 fsw, only moderate work RMV no greater than 40 Lmin should be accomplished.