fit easily into your hands in you cupped your hands, but don't touch them cuz they'll sting the snot out of you - even while dead..
However, I have seen a few that were HUGE hiding under coral heads and whatnot.. like two feet long - that's crazy huge for a Lionfish.. I have TONS of Lionfish video, but haven't ever posted any.. unfortunately, those videos were pretty much their the last thing they ever did.. its amazing that to buy one, you'd shell out hundreds of dollars, but on a dive in the Caribbean, you kill as may as you can.. if you don't, they will destroy the entire ecosystem..
Friendship is like peeing your pants.. Everybody can see it, but only you can feel the warmth..