Let me add one more option to the list of available boating safety courses. The State of NH puts on an 8 hour course at various locations throughout the year. During the Spring and Summer there are there are courses offered in Wolfeboro, Moultonborough, Gilford, Laconia and other towns thoughout the state. In the Fall and Winter there are fewer options.
See the web site for more details and schedules.
http://www.nh.gov/safety/divisions/ss/boatinged/