An inflatable mast couplable to an underwater vehicle includes a flexible material defining an interior volume, a head structure, and a spring coupled to at least one of the flexible material and the head structure. The flexible material is designed to be filled with air to form an inflated mast structure that extends away from the underwater vehicle. The head structure is disposed at a distal end of the inflated mast structure and in some cases has a rigid shape that forms a panel having an outer surface that is flush with an outer surface of the underwater vehicle, when the mast structure is deflated and stowed. The spring is designed to provide a tensile force on at least one of the flexible material and the head structure when the flexible material is inflated to form the mast structure. A system includes the inflatable mast and a pump.