The throawable requirement may simply be a reflection of USCG requirements for boats of our size. I remember checking and noted that it's required for my 18, so I carry one in my tramp bag. It's not too hard to get at, but I'll agree that keeping the boat on its feet might be more important.

What good would a throwable be? Well, perhaps in a lot of cases people sail with vests that don't provide much of a margin of flotation. In waves/chop extra flotation could be a help in keeping somebody's head above water. I imagine the Worrell guys wear better vests than a lot of the rest of us.

I also keep a righting bag hooked up and stored under my tramp bag, but more for the purpose of potentially using it as a drogue to slow down the drift in a case where I've capsized and the crew has been separated from the boat (can't right it on my own, drifting away from crew...).

The one time I used my throwable was to to toss it to another team that had capsized to use to try to float the mast...