Effects of alcohol and caffeine on maritime navigational skills

Twelve experienced navigators participated in an experiment to determine th e effects of alcohol, caffeine, and an alcohol+caffeine mixture on performa nce during the following tasks: visual search, the search and location of i tems on a navigational chart (chartsearch) and the solving of maritime navi gational problems. Alcohol (75 mi) produced impairment in performance on vi sual search (p<0.05) and navigational problem-solving (p<0.01). Caffeine wa s found to enhance performance on visual search (p<0.05) but not on the cha rtsearch, although a significant correlation was found between performance on the two tests (p<0.05). Caffeine was not found to improve the accuracy o f navigational problem-solving (p>0.05). Neither alcohol nor caffeine had a ny significant effect on the speed of problem-solving (p>0.05).