Small- and mid-scale laboratory tests were undertaken to investigate the behavior and cleanup of spills of waxy crude oils at sea. The results indicate that the behavior of such oils is very different from that of conventional oils. This difference is likely due primarily to the precipitation of waxes, asphaltenes, and other unknown resinous compounds as the oil evaporates or as environmental temperatures drop. Thus, the oil spreads, evaporates, and naturally disperses very slowly, or in the extreme, even gels into a semisolid mass. Waxy oil spills can be expected to survive on the sea surface considerably longer than an equivalent spill of conventional crude. The results of simple countermeasure tests suggest that waxy crude oil spills will be difficult to clean up, since they are very viscous, do not adhere well to oleophilic surfaces, and are extremely resistant to chemical dispersants.