Vehicle adapted to be advanced in a fluid

A vehicle adapted to be advanced in a fluid by deforming itself progressively along its length, said vehicle comprising a head including means for compressing a fluid, a body connected to said head and including a flexible and deformable envelope, and means coupled to said fluid compressing means for applying radial and longitudinal forces to said body at spaced locations along the length thereof to form a continuously generated progressive wave along said envelope which serves to propel the vehicle in the fluid, said means for applying the forces including toroidal muscle elements coupled to said envelope and selectively fed with compressed fluid for producing radial forces to deform the envelope radially at said locations and longitudinal muscle elements coupled to said envelope and selectively fed with compressed fluid for producing longitudinal forces to deform the envelope longitudinally at said locations.