Under 12' a sailboat without a motor doesn't get registered.
I have a C&L Echo sailboat that is 11' 11 3/4" length so it does not have to get registered because it is less than 12' and has no motor. The rudder is not added when measuring the length, it is just the hull.
Between 12' and 20' and without a motor, a sailboat is required to get an annual NH registration that costs about $40/year and displaying either the yearly sticker or the sticker and the bow numbers is okay.
Seemingly, this proposed kayak law would lower the registration fee for sailboats 12' to 20' without a motor from $40 down to $10 per year.
In actual practice, it is not too unusual for NH sailboats, size 12'-16' without a motor to go without an annual registration sticker for years and never ever get stopped? ...
