Field Sobriety Testing in the Marine Environment
While field sobriety testing creates legal and factual issues for DUIs, FSTs on the water provide another layers of complex legal, scientific and factual issues. Important to remember, the BUI statute specifically states that an officer shall administer field sobriety tests only when circumstances permit. RCW 79A.60.040. Rarely, are BUI arrests, commenced by routine stops, effectuated without the use of some form of field sobriety testing.
Law enforcement is almost in a rush to make arrest decisions. In their hurry to investigate, they rarely communicate the voluntary nature of these tests. Since boating is a recreational activity, it rarely is done alone. For these reasons, you should speak with any and all individuals on your boat in order to determine, what, if anything, was communicated to the operator to inform them that they were under no obligation to take the field sobriety tests.

As for the “science” behind FSTs on the water, the research is sparse and incomplete at best. Unlike the now “standardized” field sobriety test battery established by the National Highways Traffic Safety Administration (NHTSA), testing in the marine has only been the subject of one published study. Amazingly, this study concludes that the accuracy of the FST battery is not degraded in the marine environment. However, much like the studies used to “scientifically validate” FSTs on the side of the highway, this lone study is riddled with contradictions and assumptions simply not supported by common sense. Whereas the litany of studies involving DUI field tests have demonstrated that only three tests are accurate predictors of certain blood alcohol levels, apparently in the marine environment, a hole slew of tests serve this purpose. Included in the study, along with the three NHTSA standardized tests, (HGN, One Leg Stand and Walk and Turn) and found to be accurate, was the Alphabet, Hand Pat, Finger Dexterity Test, Finger to Nose and Count Backwards Test. Amazingly, while NHTSA has found only three of these tests to be accurate indicators to law enforcement, while conducted on flat, level pavement, the Coast Guard found all of the above-mentioned tests to be accurate when conducted in the marine environment.
Administration of BUI Field Sobriety Tests
Per this “study” on-boat testing will take about 15 minutes. This will include the administration of the HGN test while on a boat. This, of course, contradicts nearly all published studies on the HGN test, which require an individual to stand upright, not sway and keep their head still. Upon showing signs of intoxication, the study recommends that law enforcement secure the vessel and take the subject to land. Upon arriving, they are instructed to give the subject only ten minutes to obtain “land legs.” After magically becoming adjusted from being on the water all day, the subject is then given the one leg stand and walk and turn test. While the study will attempt to downplay the need for on land testing, we cannot ignore that the study itself showed that one third of the officers significantly improved their arrest decision when utilizing on land testing. Local law enforcement has not yet attempted to wrap marine FSTs in the aura of science that has been so cleverly done in driving cases.