Abstract
Objective
To investigate if a handheld sound navigation ranging (SONAR) device significantly reduces the median duration to locate a missing diver. A secondary objective is to determine the effect a rescue adjunct has on the participant's confidence in performing a search for a missing diver.
Methods
This Internal Review Board-approved, prospective, crossover study used a voluntary convenience sample of 10 self-contained underwater breathing apparatus (SCUBA) divers. Participants conducted both a standard and modified search to locate a simulated, missing diver. The standard search utilized a conventional search pattern starting at the point where the missing diver (simulated) was last seen. The modified search used a SONAR beacon to augment the search. For each search method, successful completion of the search was defined as locating the missing diver within 40 minutes.
Results
Twenty total dives were completed. Using a standard search pattern, only 1 diver (10%) found the missing diver, taking 18 minutes and 45 second. In the SONAR-assisted search group, all 10 participants (100%) found the missing diver, taking an average of 2 minutes and 47 seconds (SD 1 minute 20 seconds). Using the Nonparametric Related Samples Wilcoxon Signed Rank Test, actual times between the SONAR group and the standard group were significant (P < .01). Using paired samples t-tests, the SONAR group's self-assessed confidence increased significantly after using the SONAR (P < .001), whereas the standard group decreased in confidence (P = 0.111).
Conclusions
Handheld SONAR significantly reduces the median duration to locate a missing diver as well as increasing user confidence in their ability to find a missing diver when compared to standard search and rescue techniques.