The objective of this work package is to improve prediction of forces and response of vessels operating at zero or low speed in heavy seas. In these circumstances linear theory is insufficient. Work will be done to develop methods to represent non-linear forces and motions. Special problems such as broaching and capsizing in following seas, non-linear wave kinematics, green water and wave slamming will be investigated. Numerical results will be validated using model test results.

Another activity will investigate how model test results can be use to develop empirical methods for estimation of different types of forces and moments on new ship designs.