'Sly Bob' was a British naval deception in North Africa to create a type of collapsible dummy submarine which could be deployed in areas in which it might attract the attentions of Axis warplanes and thereby persuade them to waste their efforts and ordnance on a 'target' of no real value (February 1943).

On its trials in the Gulf of Suez, the 'Sly Bob' dummy caught the attention of a passing British destroyer, which summoned warplanes and a destroyer carrying depth charges, and the dummy was nearly attacked and destroyed. Only the single prototype was constructed before the realisation of its impracticality led to the cancellation of the project.