Extended Range Underwater Loudhailer for Port Security Applications
COAST GUARD RESEARCH AND DEVELOPMENT CENTER GROTON CT
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The U.S. Coast Guard CG has developed an Integrated Anti-swimmer System IAS to aid enforcement of security zones around high-value maritime assets. The IAS includes a diver recall system to issue verbal warnings and commands as the first response to a detected underwater intruder. However, the range of the recall system does not meet the CG s requirement of 500 yards for security zone enforcement. Consequently, this system must be deployed from a boat in close proximity to an intruder. This limitation consumes valuable time before a response is initiated, and might not be completely effective when multiple intruders are present. This report describes the development and prototyping of a portable underwater loudhailer having an effective range goal of 500 yards. This loudhailer was designed and evaluated through a series of technical reviews, acoustic measurements, and field tests using divers in a realistic environment to measure the intelligibility of warning messages broadcast underwater. Design details, test procedures and test limitations are described, along with environmental and safety considerations. Test and evaluation results are presented, and are used as the basis for a set of recommendations toward maximizing operational performance of the underwater loudhailer.
- Military Operations, Strategy and Tactics
- Voice Communications