You have kids whose parents actually encourage them to kayak??
Usually, it's my mom telling *me* not to die out there, or flipping out because we're boating in December and she's convinced we're all going to get hypothermia and drown.... and I'm 27, BTW!
That being said, though, PhilBob does have a point, especially when it comes to 14 y.o. girls. That's a very delicate time in a young girl's life, and at that age, either you're incredibly insecure, or 100% gung-ho/ rebellious/ hellbent on proving "something" (it may work similarly for young men, but I'm with Helio, above-- I don't claim to understand fellas my own age, much less, guys who're alot younger with alot more hormones and emotions flowing). To a 14 y.o., what's far more important than anything else is having someone around who accepts and is cool with you, who's encouraging, who reassures you and builds you up.... rather than having one more adult or peer telling you what to do or how you're doing it all wrong (think parents, teachers, coaches, media, etc).
I think it's just a delicate balance, and maybe you need to assess each student before dropping the "death threat" on them.... if she's a tough girl, it's like COUNT said, it may just be enough to provide that additional incentive?? If she's like most 14 yr old girls, though, she's so busy worrying about making sure her ass isn't too fat, that she has the right brand of jeans, who she's meeting at the mall after getting out of the pool, and if that cute boy in algebra is really going to call by the end of the week, that the whole "death card" could just end up adding another MAJOR stressor to her already hectic and complicated life??
Just my $.02.....