Systems and methods for determining the position of a buoyancy element in a marine survey are described in which a passive reflecting material is disposed on the buoyancy element to enable a radar on the vessel to detect the position of the buoyancy element. A housing aperture extends about a central axis of the housing body. The construction of the pressure vessel includes multiple fiber plies. Pedals and crank arms can mount to the second gear, which is slidable relative to the first gear to vary the position of the second gear relative to a seat mounted to the frame. The detachable connection comprises a rotating hook and a fixed hook which automatically interengage and disengage. The shield is positioned below the flame during use to lessen heat transfer from the flame to the underlying support surface.