Development of Sobriety Tests for the Marine Environment

Abstract

Six seated tests were evaluated in the laboratory to determine whether they would be feasible for use on the water as sobriety tests to measure impairment from alcohol at blood alcohol concentrations (BACs) of >0.08%. The standardized field sobriety tests (SFSTs) currently used at roadside are not suitable for the marine environment; marine law enforcement officers are left with insufficient methods to assess impairment on the water. One hundred fifty-seven participants were randomly assigned to a BAC group: 0.00%, 0.04%, 0.08%, and 0.12%. Six tests were administered to the participants by experienced law enforcement officers. Neither the testers nor the participants were privy to the participants' BACs. A variable called BAC status (N = 138) was obtained by dividing the average BAC into two groups: BAC < 0.08% and BAC ≥ 0.08%. A combination of four tests—horizontal gaze nystagmus (HGN), finger to nose (FTN), palm pat (PP), and hand coordination (HC)—correctly classified 82% of the BACs ≥0.08% and 67% of the BACs <0.08%, for an overall percentage correct of 72%. Four individual tests also predicted BAC status: HGN, FTN, PP, and HC. Four tests in combination and individually discriminated BAC status, although the overall percentages of accuracy, sensitivity, and specificity of the tests were below what was typically reported in literature on the roadside SFSTs. With the proper refinements, the four tests may assist marine officers with assessments of alcohol-related impairment in recreational boaters.