I live in Florida but spend the summers in NH and I was concerned about whether the state would honor my Florida boating license so I called them and this is what they told me. If the course has been approved by the National Association of State Boating Law Administrators and is recognized by the US Coast Guard, it is valid in NH. I asked them if a citizen of NH took an online exam from any other state and pass it, would it be OK in the State of NH and they said that as long as it met the above mentioned criteria, it was valid in the State of NH.
I then asked about Massachusetts and they said that they don't honor the licenses from MA because they aren't sanctioned by the state so they wouldn't meet the above mentioned criteria, however, if a Massachusetts resident took a course that was approved by the NASBLA, the State of NH would honor it.
According to the web site
http://www.americasboatingcourse.com...oating_law.htm the State of Maine does not have a mandatory course so I'm not quite sure where you might get a license unless you take a USCG test. If you take the online course offered in FL, you could use it in NH. It is a very comprehensive course, costs $14.95 and you have to get an 80 on a 50 question final test to pass. You can take the test as many times as you want until you pass it. There is alot of good info there.
Try this website:
http://www.boat-ed.com/abc/abc_speci...dfs/nh_law.pdf
Note the section "Who May Operate a Vessel" . It is very specific about what the State of NH will accept and doesn't mention anything about proctored exams.