Some people are comfortable, and some kids are better listeners than others. My parents are on a lake, so my kids are pretty water saavy as well - but they aren't great swimmers yet and I got lost at SAB myself. The problem with SAB is the sight lines, the size, and the unexpected depth - particularly around the lazy river....it isn't easy to watch one kid in the "pool" while the other enjoys the slide.
We enjoyed it a lot when the kids were four and five and we were in the water with them. We look forward to enjoying it again when then are 11 and 12 (or so) and we can say "meet us here in an hour." But for the next several years (they will be six and seven next trip), we will be avoiding BCVs and looking for pools where the kids can have both freedom and supervision (i.e. I can watch them from my chair regardless of where they go). As I said, its a lovely pool.....just one certain to give Moms like me with kids like mine a lot more grey hair! (Waterparks cause the same sort of reaction in me - but we will still spend the day at the waterpark as a family - I like to spend the afternoon at the hotel pool with the kids in the water and me not getting wet).