In 2008, the United States Coast Guard counted 4,789 accidents in which 709 people were killed, 3,331 people were injured. Not surprisingly, the month with the most boat accident deaths is August. The economic loss that comes with boat accident is also staggering: $54 million alone in just recreational boating accidents.
Alcohol was found to be a factor in 17% of boat accidents. Thankfully, only one Maryland death in 2008 was attributable to alcohol.
You can find more boat accident statistics here.