transient tax

What percent sales tax did you have to pay on the purchase of your vessel in NC? Usually, that is the starting point for understanding whether you might be liable at some point for additional taxes in another state.

For instance, I paid 6% on the purchase price of my vessel in Maryland. Another state would only generally impose a tax if Maryland's tax is less than that state charges. They would make me pay the difference between their tax and the Maryland tax if I stayed more than "x" number of days or months.

Although I can't find the citation I believe you're OK in NY for 183 days if you are not a resident. However a resident must register within either 20 or 30 days. With that said, I've never seen or heard of anybody having an issue. It's much different than in Florida where they have a ton of people from other states and countries who want to leave their boats there year-round or at least every winter, all-winter. My guess is that you'll find the same in Conneticut.

Maine is the state in the Northeast with a very short stay before paying taxes.......

Excise tax on boats in Maryland is 5%.

The rest of your point is correct. You're in a better position in most states if you already paid tax somewhere.