Daytime Distress Signal Effectiveness
Abstract
This report details work on behalf of the Coast Guard Office of Design and Engineering Standards, Life Saving and Fire Safety Division (CG-ENG-4) to determine the daytime efficacy of an electronic visual distress signal, particularly as a comparable alternative to pyrotechnic flares, for recreational vessels in the United States (US). The Office of Search and Rescue (CG-SAR) and the Office of Boating Safety and Auxiliary (CG-BSX) played a major role in helping frame the desired test objectives. The report presents methods and results of field tests comparing conspicuity of hand-held flares, an orange distress flag, a signal mirror, human hand-waving, and a flashing, light-emitting diode (LED) signal. The LED signal characteristic is a group alternating, cyan (Cy) and red-orange (RO) color, 4 Hertz (Hz) flashing the SOS pattern at 50 candela (cd) effective intensity, as recommended in earlier work. The project team conducted two full-scale field tests that yielded 759 human subject ratings of distress signal conspicuity at a one-half mile range. Test results varied greatly between sunny and cloudy conditions, with observers rating almost all signals as more conspicuous in cloudy conditions.
Document Details
- Document Type
- Technical Report
- Publication Date
- Dec 01, 2019
- Accession Number
- AD1121486
Entities
People
- E. A. Murphy
- M. J. Lewandowski
- M. K. Steinhaus
- V. A. Reubelt