The potential of controlling wave energy converters, (WEC), by deterministic prediction of large damaging waves is introduced and shown to offer very substantial increases in the annual average power output of such devices. Results obtained for idealised WEC models show that the potential exists for this increase to be at least a factor of two. Numerical simulations of actual dynamical models for both point absorbers and directionally sensitive devices employing practical control strategies show that most of this potential can actually be realised. The control of large scale wave farms using quiescent period predictive control is likely to be most cost effective using master/slave WEC systems. To achieve the computational savings that will allow this strategy analytic approximations are required for the response of WECs with time varying coefficients, preliminary forms of these have also been introduced. (C) 2010 Elsevier Ltd. All rights reserved.