It is mandatory. If they were caught they would be fined and should be. Not sure what the fine is but it should high dollar. For any one not putting their kids in proper life vest the fine should be high to prevent it in the future. I feel the same way about seatbelts for kids in cars and trucks. The fines are not near high enough to make parents make sure they are buckled up every time they leave the driveway. I hate it when I drive across town and see young kids climbing from the front seat to the back or riding on a parents lap behind the wheel or in the pasenger seat on someones lap. Not much we can do but cringe and say a little prayer that they make it where they are going safely. Stiffer fines I feel would help reduce this.