A small number of retrospective studies on the etiology of specific fears have obtained findings consistent with a biological (non-associative) explanation of fear acquisition. Unfortunately, reliance on imperfect memory to recall conditioning events which occurred many years earlier limits the conclusions that can be drawn from such data. The present investigation attempts to overcome this methodological shortcoming by examining the relationship between water trauma (i.e. conditioning) and water skills (e.g. swimming) before the age of 9 and the presence of water fear and phobia at age 18 in a longitudinal birth cohort. We found no evidence of a relationship between water confidence and water trauma up to the age of 9 and fear of water at age 18. Similar findings were obtained for water phobia at age 18 with the exception that study members who were less able to immerse themselves in water with confidence at age 9 were more likely to report water phobia at age 18. Associative and non-associative explanations of these findings were discussed.