I use an old pair of 4 ml neoprene chest waders for beach fishing when it's cold. You have to be sensible and not venture to far in. They are far warmer than nylon, can stand up to blackberries etc much better and relatively easy to repair if they do get torn. Thigh waders - great way to get a boot full of water IMHO. Go for chest waders with a wading belt for safety.