Yeah ... I don't see how a state that requires THEIR citizens to tag their boat trailer to require out of state boat trailers be tagged, when those out of state trailers are not required to be tagged in their home state.
I mean, all but 19 states require vehicles have a plate on the front and back, but you don't hear about people getting ticketed for only having a license plate on the back when they're in those other 31 states.

I mean, I still have my trailer license plate ... but I took it off when I put the retractable tie downs on my trailer. Guess I'll just not spend my money in those states that would ticket me for not having trailer plates.