Millions of parents take their children boating each summer. For the safety of the children -- and for the piece of mind of the parents -- kids wearing life jackets should be a must.

"Just having them on board isn't good enough. Life jackets on a boat are like seat belts in the car -- they don't save lives if they aren't worn," said Jim Ellis, safety director for BOAT/U.S. (Boat Owners Association of the United States), the nation's largest organization of recreational boaters.

BOAT/U.S. has the following suggestions for buying a life jacket for the kids:

--Children's life jackets are sized according to weight: under 30 pounds, 30-50 pounds and 50-90 pounds. Many also specify a chest size. Choose the one that's right for your child.

--The brighter the color, the more likely your child is to want to wear the life jacket.

--The life jacket should fit snugly. Have your child try it on in the store. Lift the shoulders of the jacket to make sure it doesn't slip over the chin or ears. If there's more than three inches between the child's shoulders and the life jacket, it's too big.

--After the purchases, have your child wear the life jacket in the water and adjust the straps as needed for the proper fit.