I have heard stories of these guys jumping out of the water and slamming into kayakers before.
They tend to tear large chunks of flesh off much like a piranha does.
These are just little guys because the big ones usually like to travel alone, not in packs like this.
They are probably not as dangerous as some make them out to be as they rarely attack people, but they are no joke if you get one on the end of your line and you try to take the hook out of its mouth.
Good luck.