Abstract: An underwater device for generating a vortex ring includes a liquid chamber, and a fluid or air chamber contiguous to the liquid chamber and separated by a partition wall. The liquid chamber includes a generally rigid section and a compressible or flexible section. The rigid section includes an opening for selectively loading the liquid chamber with a liquid and for discharging a vortex ring therefrom.

Abstract: An underwater device for generating a vortex ring includes a liquid chamber, and a fluid or air chamber contiguous to the liquid chamber and separated by a partition wall. The liquid chamber includes a generally rigid section and a compressible or flexible section. The rigid section includes an opening for selectively loading the liquid chamber with a liquid and for discharging a vortex ring therefrom.

Abstract: A self-priming underwater device for generating a vortex ring entrained with a fluid, includes a handle, a housing including front and rear sections, a trigger for supplying a fluid to the housing, a piston assembly in the rear section of the housing and including a yoke, a piston movable in the yoke, and a plate for displacing a liquid, and a splitter for diverting one portion of the fluid to the piston assembly to thereby move the piston. The front section of the housing includes an opening for discharging a vortex ring therefrom, and a fluid supply member is positioned adjacent the opening for supplying another portion of the fluid to be entrained in the vortex ring.