Delaware surf zone injuries and associated environmental conditions

Surf zone injury and environmental condition data were collected concurrently during the summer of 2014 along the Delaware coast. Documented injury data included injury type, gender, age and activity, while measured environmental conditions included local wave height, wave period and foreshore slope. Daily water user counts were used to normalize injury rates relative to the number of beachgoers at risk. There were 280 injuries over 116 sample days along the entire Delaware coast and 169 injuries over 82 sample days within the 5-beach focused study area where water user count data were available. Injuries were not distributed randomly as tested against a Poisson distribution and occurred in clusters with up to 15 injuries occurring in a single day. There were 32 serious injuries (cervical fractures, spinal cord injuries) and 1 fatality. Water user counts throughout the course of a day exceeded 25,000 on busy weekends such that the mean injury rate was 0.02 %. Men were twice as likely to be injured relative to women, and the mean injury age was 32 years old. Tourists were six times more likely to be injured compared to local beachgoers. Wading (44 %) was the dominant injury activity followed by body surfing (20 %) and body boarding (17 %). Direct correlation between injury occurrence or injury rate and any environmental factors was weak (highest squared correlation coefficient < 0.12), but the highest injury rates were associated with moderate wave height (0.6 m) with lower injury rates for both smaller and larger waves. Lack of direct correlation between injury occurrence or injury rate and environmental parameters suggests there was an important (and as yet undetermined) human element that also dictates the injury rate. Additionally, the high proportion of injuries to tourists may require alternate strategies in local beach safety and injury awareness campaigns.