I took the test, and got the safe boating cert. here in MA a couple of years ago (offered by the Environmental Poilce). They did an excellent job and I recommend the course highly to anyone who boats here in MA. Having said that, I've found it very useful to use the NH
practice test as a way of refreshing my memory. I was surprised at how much info fell off my short-term memory. Also, the nav. markers work a little bit differently too.
After I got over my initial irritation over being "inconvenienced" by having to take a course, I was somewhat surprised that the cert. requirement is a recent trend. If you run in to trouble on a boat, you can't just pull over.