It is probable that within the next ten years marine transport technologists will be faced with some difficult choices in relation to ship propulsion for an era of high fuel prices. They will have to consider (i) the continuation of conventional power driven vessels with greatly improved engines, or low speed operations; (2) the development of high speed nuclear powered ships; and, (3) the use of sail. Whether the latter will be adopted to any significant extent for ocean transport will depend on the oil supply situation in the 1980s and 90s; developments in ships' engines; and, more importantly, the philosophy then prevailing relating to the conservation of the world's non-renewable resources.