Abstract: The International Association of Classification Societies has updated the North Atlantic wave scatter diagram and supplementary requirements. A series of ships, including bulk carriers, oil tankers, container ships, ore carriers, LNG carriers, PCTC ships and passenger ships, were used to analyse the influence of the updated wave scatter diagram on a ship's wave load through long-term wave load prediction. The results of the analysis show that, compared with the original North Atlantic wave scatter diagram, the new diagram and supplementary requirements have a different impact on different ship types, typically decreasing by 0~40%. The results of this study provide a reference for determining the extreme wave load of ships above the new scatter diagram.