Chapter X 



STUDIES OF DIVER COMMUNICATION AND RETRIEVAL 



Harry Hollien, Ph.D 



and 

 Howard Rothman, Ph.D. 

 University of Florida 



ABSTRACT 



The Communication Sciences Laboratory has been conducting an 

 extensive program of research on diver communication and sound 

 localization, and has recently extended the research to include 

 diver detection, recall, and navigation. A series of studies 

 was conducted at Lameshur Bay and at Buck Island, Virgin Islands. 

 The series included studies on diver communication, navigation 

 by auditory methods and diver retrieval. 



INTRODUCTION 



Divers are not efficient workers in an undersea environment for a number of 

 reasons; viz., 1) the absence of inter-diver communication and diver-to-surface 

 communication with support personnel, 2) difficulties in locating and recalling 

 divers when they are operating underwater, and 3) a lack of reliable methods of 

 underwater navigation. 



Thus, it is clear that practical communication, navigation, and retrieval sys- 

 tems are vital if extensive free-diving activities are to become feasible. 

 Moreover, it has become apparent recently that acoustic approaches have the 

 greatest potential for development of such systems. Accordingly, the Communi- 

 cation Sciences Laboratory at the University of Florida has been conducting an 

 extensive program of research on diver communication which recently has been 

 expanded to include diver detection, recall, and navigation. 



In the past, much of the research conducted was either basic or specialized in 

 nature, or was carried out in fresh water, primarily in connection with Navy 

 programs. In time it became necessary to find a marine environment that pro- 

 vided a relatively shallow, warm, salt water research site- -one that included 

 1) good project support, 2) a complement of experienced divers, and 3) a gener- 

 ally protected (especially acoustically) underwater environment. Nearly ideal 

 conditions were obtained at TEKTITE II, both at Lameshur Bay and at Buck Island, 

 The Buck Island facilities were provided by the College of the Virgin Islands. 



The Communication Sciences Laboratory conducted the following projects at 

 TEKTITE II. 



1. Studies of Diver Communication 



a) Phase-2 of an English based diver lexicon. 



b) Mixed gas (shallow water) intelligibility. 



c) Diver-to-surface intelligibility of communication systems as a 

 function of range. 



X-1 



