Shock pressure attenuation in water ice was studied at an impact pressure below 1 GPa and a temperature of 255 K. The observed shock wave showed a multiple shock wave structure: A precursor wave was followed by a main wave, which had a longer rise time and higher amplitude. The Hugoniot elastic limit (HEL) of water ice was measured to be in the range, from 0.1 to 0.3 GPa when associated with precursor waves traveling at 3.86 km/s. The peak amplitude of the main wave Pm was observed to decrease with its propagation x from 3 to 60 mm (from 0.4 to 8 times as large as a projectile radius) in two series of experiments in which initial shock pressures Pi at the impact point were 0.60 and 0.87 GPa. The Pm was described as the power law relation Pm/Pi = (x/2.6 mm)-0.89. The precursor wave disappears as the Pm attenuated to a pressure <0.1 GPa. The measured wave profiles were used to calculate the loading path of water ice in shock compression between the HEL and 0.6 GPa. The loading path obtained by Lagrangian analysis was closely consistent with previous Hugoniot data regarding water ice. ¿ 2001 The American Geophysical Union.