An assessment of the condition of waterlogged wood is important to determine the best method for its conservation. The assessment of material from the hull of the Mary Rose using a number of analytical techniques is discussed. These include moisture content ash content, chemical analysis and the use of a pilodyn which is an impact density wood test instrument. The timbers show considerable variation in the extent of decay but consist, in general, of a soft deteriorated outer layer of variable thickness surrounding a firm, less deteriorated core. Figures, graphs tables 14 references.