Over the course of British history, many ships were built of English Oak (Quercus robur), because it was widely available across the country for much of the historic period when ships were built of wood . We have obtained samples from a sequence of vessels built from English Oak spanning four centuries, ranging from the Tudor Mary Rose, commissioned in 1509 and launched in 1511, to the Thames sailing barge (SB) Tollesbury, built in 1901 (Table ). Samples were collected from areas of the ship which were continuously exposed to water (typically seawater) and studied using thermally assisted hydrolysis and methylation combined with gas chromatography-mass spectrometry (THM-GC-MS).