Marine Patrol stops NH boater for failure to display stern light. During safety check officers note slurred speech, odor of alcohol and lethargy. During field sobriety tests on Marine Patrol vessel operator begins to display further signs of impairment and/or an oncoming medical condition. Boater faints and goes unconscious at conclusion of field sobriety testing. Defense sucessfully argues underlying medical condition caused boater to appear impaired and ultimately pass out. Government cannot rule out underlying medical condition as cause of symptoms. Not guilty verdict in this NH DWI charge following trial.