GB-4 was a precision guided munition developed by the United States during World War II. It was one of the precursors of modern anti-ship missiles. Following German success with the Hs-293 and Fritz-X, the U.S. began developing several similar weapons, such as Felix, Bat, Gargoyle, GB-8, and GB-4. The Pacific War ended before it entered combat. A derivative, the GB-9, was intended to use a "dive-and-glide" trajectory for attacking targets like submarine pens from the side, but also did not see combat.