Describes the analysis of pitches and resins obtained from shipwreck sites, using nuclear magnetic resonance (NMR) spectroscopic techniques. Pitch samples obtained from the <i>Vergulde Draeck</i> (1656), the <i>Rapid</i> (1811), the <i>Belinda</i> (1824), the <i>Eglinton</i> (1852) and the <i>Fanny Nicholson</i> (1872) were analyzed using both proton (¹H) and carbon-13 (¹³C) NMR spectroscopic techniques. Spectra obtained from these samples were then compared with those obtained from a sample from the <i>Mary Rose</i> (1545), authentic Stockholm tar (pine tar obtained by the destructive distillation of <i>pinus sylvestris</i>) and Norway spruce wood tar (<i>Picea abies</i>). The sources of each of the pitch samples from Western Australia shipwreck sites were identified. Information concerning the preparation and degradation of the pitch samples are discussed. Organic materials obtained from the <i>Sirius</i> wreck site were also examined spectroscopically. One sample, extracted from an axehead, has been identified as a mixture of di-and tri-glycerides while another sample, originally thought to be amber, has been shown to be a complex mixture of aromatic compounds.