Atmospheric muons play an important role in underwater/ice neutrino detectors. In this paper, a parameterisation of the flux of single and multiple muon events, their lateral distribution and of their energy spectrum is presented. The kinematics parameters were modelled starting from a full Monte Carlo simulation of the interaction of primary cosmic rays with atmospheric nuclei; secondary muons reaching the sea level were propagated in the deep water. The parametric formulas are valid for a vertical depth of 1.5-5 km.w.e. and lip to 85 degrees for the zenith angle, and can be used as input for a fast simulation of atmospheric muons in underwater/ice detectors. (c) 2005 Elsevier B.V. All rights reserved.