Pursuant to RSA 270-D:10, I, no person born on or after the dates provided in Table 6100-1 shall operate a
motorized vessel with any type of power motor in excess of 25 horsepower on the public waters of this state without first obtaining a certificate of boating safety education in accordance with these rules:
Here's the whole RSA:
http://www.gencourt.state.nh.us/rules/saf-c6100.html