Re: what saftey stuff is needed for a 21 footer
FIRST take the safety course-- a live one at that, where you can ask questions, not on line.
Then you'll have your list.
and they may not mention it, or at least not emphasize it, but a properly rigged anchor is your most important safety equipment for coastal boating.
Always have something you can bail with. And a hand pump. And a paddle.
Always have a light even if you never go out at night. SAR can see a minimag from miles away. I know one case where two people on a small sailboat died the bay when if all they had was a light they probably would have been fine.
Read the thread about "cheap life vests"
never, ever, consider your cell phone to be a safety device. They are way too fragile to even think they can save you. Plan as if they don't exist.
A CD is a good cheap signal device in the daytime.