Stand-up paddle boards are required to have a pfd onboard and a whistle while kayaks are required to have a pfd but not a whistle. Has something to do with the Coast Guard decision that a stand-up paddle board is a vessel .... toot-toot ...
???
And, actually wearing the pfd is not required in NH if age-16 or older, or something??? Common sense tells you to wear a pfd with a good loud whistle or maybe an air horn! Air horns come small enough to fit in a pocket on a pfd or be worn around the neck on a lanyard.