I'm only 5' tall and I know it is over my head at the bottom of the slide. It is at least 5 feet deep and maybe 6 feet. Even if I could stand at the bottom of the slide, the lifeguards won't let anyone do that. Also, parts of the lazy river are 8 feet deep.
There are lifejackets (in all sizes) for people to check out at the pool shop in the center of SAB. You just need to give your room number and you can have the jacket for the length of your stay. If you don't return it, then they charge something like $50.00 for it. There are also noodles for sale and the tubes to rent.
Our kids have used the lifejackets both times we stayed at BC. Also both times, we have been given pool noodles by strangers. Gotta love pixie dust! Once, at the end we passed the noodles on to another family. The second time, we asked the CL CMs to pass them on (it was early in the morning and no one was around) and they asked if we would be willing to leave them in the CL "loaning closet." They said they had a closet for items people may need during their stay and asked if we would leave them there. Of course, we said yes. We should have written on them or something, because I would LOVE to know if they are still being used! (That was May 2010.)
Have a great trip! So looking forward to Dec.!