He is right, Here's the Rule:
It's the Law: Before Going Out
All operators are required to obey laws that regulate your vessel's registration and operation.
Registering Your Vessel
You must have a New Hampshire Certificate of Registration and validation decals to operate your vessel legally on public waters in New Hampshire. This includes motorboats of any size (including those with electric motors) and sailboats or sailboards 12 feet in length or longer. The only exceptions are:
Sailboats and sailboards under 12 feet in length
Other small, non-motorized vessels such as canoes and kayaks
Vessels registered in other states using New Hampshire waters for 30 or fewer consecutive days
Vessels owned or operated by the U.S. government
The Certificate of Registration must be on board and available for inspection by an enforcement officer whenever the vessel is operated