This project is one of the small number of proposals selected by an industrial consortium in collaboration with EPSRC to go forward as full proposals to the EPSRC Launch and Recovery Co-Creation Initiative. It involves a collaboration between Exeter and Southampton Universities, Scripps Institution of Oceanography (USA), BAE Systems, MOD and OCEANWAVES (Germany). It is supported by a mentoring/dissemination group comprising: BAE Systems, MOD, SEA Ltd, Zenotech and ESI Group. The practical driver is to enable a wide range of wave limited maritime operations to be carried out safely at higher sea states than is presently feasible. Particularly important examples are launch and recovery operations from mother ships of small boats, manned and unmanned air vehicles, and submersibles. The research concerns the two coupled areas of: (a) predicting the actual shape of sea waves, termed Deterministic Sea Wave Prediction and the application of this to predicting calmer periods in otherwise large seas (Quiescent Period Prediction), and (b) a comprehensive investigation of the properties of such quiescent periods and the creation of a quiescence simulator. The research involves an integrated combination of challenging fundamental new theory, simulation, large scale data analysis and experimental testing. An applications oversight, designed to facilitate post project the optimum push through to higher technology readiness levels, is provided by the industrial mentoring panel. MOD and BAE Systems are also research partners. The research will provide the predicted wave environment information required by closely allied projects within this EPSRC Launch and Recovery Co-Creation Initiative which are aimed at (a) modelling the motion of small craft in the near wave/flow field of a parent vessel and (b) control of launch and recovery operations. An alternative application of the new science is in the optimal control of wave energy converters where large increases in performance per unit cost are possible (see the impact case).