The prominent exception was the Naval Bureau of Ordnance’s “Bat” antishipping weapon, which was fielded operationally, and was one of the most impressive guided weapons developed during World War II. Design work that led to the Bat began in 1941 and evolved through various forms.
The original concept was named “Dragon”, given as the “Dryden Bomb” in some sources; one of the lead researchers on the project was Hugh L. Dryden of the National Bureau of Standards (NBS), who would later become one of the founding senior officials of the US National Aeronautics & Space Administration (NASA). It was defined as a radio-controlled glide bomb with a 900 kilogram (2,000 pound) warhead, with a plywood airframe designed by the NBS. A few were tested in 1942, but the Navy wasn’t enthusiastic about the idea of the launch aircraft being forced to stick around up to weapon impact and quickly gave up on the concept. A TV-guided variant named “Robin” was then tested, but TV was simply not ready for combat at the time.
The research effort then moved on to the “Pelican” or “Special Weapons Ordinance Delivery (SWOD) Mark 7”, which was intended for antisubmarine warfare. It carried a depth charge for attacks on surfaced U-boats, and was fitted with a “semi-active radar homing (SARH)” seeker that homed in on reflections from a radar beam provided by the launch aircraft. Use of a depth charge set to go off at shallow depth provided a higher “kill probability” against a submarine than a straight HE warhead. Hitler’s U-boats were decisively defeated in the spring of 1943 and the Pelican itself did not go into production.