A collection of self-diffusion data is reported in an Arhhenius representation, vs. . Data come from bulk water (as blue symbols [27,64,65,66,67,68]), fused amorphous water (dark red [32]) together with MCM confined water (NMR [30] and dielectric relaxation data [69], dark yellow); data coming from the theoretical study, obtained from the evaluated by using the Adam–Gibbs (dark pink open circles), are also reported [45]. These data cover a very large T- range from 373 to 120 K, with an overall variation of about 12 orders of magnitude, without the presence of any singularities. The two straight lines indicate the strong behavior at the lowest temperatures.