outgrowing baby tub--what's next?

With both our kids, once they could sit fairly well, I put the grips/non-slip things on the bottom of hte tub. I never leave them only and never had any problem or fear for them. in fact in our old house we had a huge walk in custom shower and I would just sit our daugther on the floor of the shower. Her and I got clean together and until we moved she rarely took baths.