Divers are increasingly required to perform 'safety to life' calculations which, if incorrect, may result in a serious incident. The application of an 'old fashioned' manual computational technique, the Nomogram, is proposed as a cheap and simple tool for performing safety to life calculations. The Nomogram is friendly to non-mathematicians, applicable to the marine environment and may significantly reduce the risk of calculation error. Example Nomograms are illustrated and the advantages for improving diver safety presented.