Please read this - many preventable drownings and horrible injuries are caused by entrapments in pool/hot tub drains, even for kids and adults who are great swimmers. A new law went into effect Dec. 19. I highly recommend checking out the photos of "approved" drain covers and making sure that the pools and hot tubs you use and your kids use are safe. Ask the owner/operator if they have anti-entrapment drains.
You can find out more at http://www.usa.safekids.org/water/pool.html