1. A method is presented which allows the jet thrust and motion of a cephalopod to be calculated from basic information on its shape and material properties.
2. A simple model is used to illustrate the technique, and the results are compared with experimental data for Loligo vulgaris. Agreement between theoretical and experimental results is shown to be reasonably good.
3. This approach could be applied to other cephalopods and other animals using jet propulsion.