A must for the summer, either to take on holiday or just your local swimming pool, is
swim nappies and tankini tops from Imse Vimse. They are a great little nappy, pull on style, with a popper fastening at one side for easy removal, much nicer to wear and less waste than soggy disposable swim nappies (would you wear disposable swim wear?)
These are slim fitting, and worn on there own (no need for a nappy underneath) and do a great job of containing solids, should your child feel the need in the swimming pool! They come in sizes medium, large, extra large, super large and junior and a variety of different patterns.