A pressure-energized ring joint gasket such as a CX gasket for a clamp or other connector includes a cylindrical inner surface oriented toward adjacent sections of a subsea stack that are to be joined by the connector, wings that taper away from the cylindrical inner surface and end in a rectangular shoulder, wherein a portion of the rectangular shoulder is removed to create a boss, an upper groove, and a lower groove, and D-rings in the upper and lower grooves. The gasket can be used to connect adjacent sections of the stack and to maintain a seal between the sections whether the external sea water pressure is greater or less than the internal well pressure. A method for using the gasket for connecting adjacent sections of a subsea stack in offshore drilling environments is also provided.