A comparison of underwater helicopter-escape lights.

The effectiveness of two types of steady and flashing lights as escape hatch indicators for submerged helicopters was compared. Measurements were taken in moderately and highly turbid water. Response time was faster to the steady lights, and they were more accurately localized. Pairs of steady lights appeared to have some advantage over single lights, but this was not true for flashing lights. Subjects found it very difficult to discern how many different locations were being illuminated.