A review of the recent progress made regarding ocean environmental data and models with uncertainties in focus is given in the perspective of marine structures' design and operations. Uncertainties of wind, waves, current, sea water level and ice data and models are discussed and recent achievements leading to improvement of their accuracy are addressed. The study includes mathematical, probabilistic, empirical and statistical models. Particular attention is given to rogue waves. Challenges related to wind data and models due to the increase of offshore wind energy installations are presented focusing on wind forecast, information about the wind profile and extreme wind events. Attention is also given to ice which is of particular importance due to the projected climate changes opening new opportunities in the Arctic regions for the marine industry. Impacts of improved accuracy of environmental description on design and operations of ships and offshore structures are highlighted.