A multiple start torpedo comprising a turbine, wherein the turbine is configured for being started multiple times to charge a battery or propel the torpedo, comprising: an aft body having an exhaust conduit defining a turbine end and a seawater end, said exhaust conduit having an orifice; and an exhaust valve associated with the exhaust conduit including: a fore section having a head defining a maximum outer diameter and a valve stem; an aft section tapered from the turbine end to the seawater end and defining a receptacle sized to receive the valve stem; and a biasing member disposed to bias the head in an extended position spaced apart from the aft section and abut the orifice in the extended position, the head and the aft section forming an inner teardrop shape, wherein: the head forms an inner bulbous portion of the teardrop shape, the inner bulbous portion being a concave exterior surface; and the aft section forms an inner tail portion of the teardrop shape; wherein the orifice of the exhaust conduit defines an orifice diameter that is less than the maximum outer diameter such that the head is sized to block the orifice in the extended position; and the exhaust conduit includes a contour having an outer teardrop shape that mimics the inner teardrop shape having an outer bulbous portion that joins the orifice toward the turbine end and an outer tail portion that extends toward the seawater end, wherein the orifice receives the concave exterior surface of the head in the extended position, and wherein the head defines a seawater catch basin oriented toward the seawater end such that seawater inflows drive the head toward the extended position. an aft body having an exhaust conduit defining a turbine end and a seawater end, said exhaust conduit having an orifice; and an exhaust valve associated with the exhaust conduit including: a fore section having a head defining a maximum outer diameter and a valve stem; an aft section tapered from the turbine end to the seawater end and defining a receptacle sized to receive the valve stem; and a biasing member disposed to bias the head in an extended position spaced apart from the aft section and abut the orifice in the extended position, the head and the aft section forming an inner teardrop shape, wherein: the head forms an inner bulbous portion of the teardrop shape, the inner bulbous portion being a concave exterior surface; and the aft section forms an inner tail portion of the teardrop shape; wherein the orifice of the exhaust conduit defines an orifice diameter that is less than the maximum outer diameter such that the head is sized to block the orifice in the extended position; and the exhaust conduit includes a contour having an outer teardrop shape that mimics the inner teardrop shape having an outer bulbous portion that joins the orifice toward the turbine end and an outer tail portion that extends toward the seawater end, a fore section having a head defining a maximum outer diameter and a valve stem; an aft section tapered from the turbine end to the seawater end and defining a receptacle sized to receive the valve stem; and a biasing member disposed to bias the head in an extended position spaced apart from the aft section and abut the orifice in the extended position, the head and the aft section forming an inner teardrop shape, wherein: the head forms an inner bulbous portion of the teardrop shape, the inner bulbous portion being a concave exterior surface; and the aft section forms an inner tail portion of the teardrop shape; wherein the orifice of the exhaust conduit defines an orifice diameter that is less than the maximum outer diameter such that the head is sized to block the orifice in the extended position; and the exhaust conduit includes a contour having an outer teardrop shape that mimics the inner teardrop shape having an outer bulbous portion that joins the orifice toward the turbine end and an outer tail portion that extends toward the seawater end, wherein the orifice receives the concave exterior surface of the head in the extended position, and wherein the head defines a seawater catch basin oriented toward the seawater end such that seawater inflows drive the head toward the extended position.