Abstract: Condensate accumulating in the combustion chamber of a marine gas exploder of the cylinder and piston type is collected by gravity flow in a sump formed in a cylinder side wall or in a face of the piston, depending upon whether the cylinder is oriented horizontally or vertically. One end of an exhaust tube is positioned adjacent the base of the sump so that gaseous combustion products flow through the sump into the exhaust tube so as to collect and remove the accumulated condensate.

Abstract: A gas exploder consisting of a rigid cylindrical lower member and a rigid upper member telescoping therein to form a chamber in which a gas explosion can take place is supported beneath the surface of the water from a float by means of low resilience ropes connected to the bottom of the lower member so as to substantially limit its allowable downward movement. The upper member includes a piston downwardly biased within the lower member by an air spring and a hollow pedestal connected to the piston and extending freely through the float above the surface of the water to accommodate fuel, compressed air and exhaust conduits communicating with the interior of the housing. The energy of an explosion in the combustion chamber is expended primarily through rapid upward movement of the piston, which compresses the air spring and then lifts the lower member. Implosion of the resultant cavitation bubble adjacent the bottom surface of the lower member generates a pressure pulse of large peak amplitude.