Before REQUIN's story continues, a brief background must be given on the radar picket program. Born out of experiences during the latter stages of World War II, the Navy began to consider placing early warning radar equipment aboard submarines. This idea resulted from the severe losses the Navy experienced during the invasion of Okinawa, where surface picket ships bore the brunt of the kamikaze assault. Faced with an abundance of new and relatively new submarines, the Navy experimented with hastily-converted surface ship radar equipment aboard submarines. REQUIN, after nearly a year in commission, and SPINAX (SS 489), while still on the ways at Portsmouth, became the first radar picket submarines in the US Navy. Envisioned to carry radar capable of controlling friendly aircraft defending against attacking enemy aircraft, directing outbound aircraft, it was envisioned that these radar picket submarines could also provide an early warning capability to the surface fleet.

Faced with problems that would last throughout the life of the radar picket program, REQUIN would encounter overcrowding problems (she retained all ten torpedo tubes until her MIGRAINE conversion) and flooding (the radar mounted on her stern would short out
quite frequently), REQUIN was subjected to another more extensive conversion as a radar picket under the somewhat appropriately named MIGRAINE Program. Designated as SSR-481in January of 1948, REQUIN would lose her four stern torpedo tubes, with the space gained in the forward part of the stern room being converted into a full-blown air control center (REQUIN vets who served aboard during the radar picket days would refer to this as the combat information center). The remaining space, where the tubes themselves once were, was converted into berthing space for the extra crew. In addition, REQUIN lost the use of the two bottom tubes in the forward torpedo room, which were converted into storage lockers. Topside, the 40 mm cannon on the aft cigarette deck was removed, with the space being taken up by an SR-2 air search radar. In addition, REQUIN received a YE-3 fighter controller beacon, located above the after engine room on deck, as well as an SV-2 low angle surface search radar. (This radar, because it was located so close to the water line near the screws, often shorted out and was commonly referred to as the "Nodding Idiot".) Finally, REQUIN also received a snorkel, which allowed her to run her four Fairbanks-Morse engines while submerged at periscope depth.

Tactics used by radar picket submarines varied, depending upon the situation. Often, two radar picket submarines would operate together and somewhat near each other. If a submarine controlling a raid had to dive to escape enemy aircraft, the other nearby picket would pick up the coverage until the original controlling sub could reposition itself and resume coverage. Radar picket submarines would often be stationed on the suspected threat axis of a raid against friendly surface ships, often at ranges of 10,000 yards or so. These boats would then control the intercept of attacking enemy aircraft, control outgoing intercepting aircraft or outgoing friendly attacking aircraft, or serve as early warning (picket) ships for the fleet.

In addition to REQUIN, SPINAX also became a MIGRAINE II radar picket. Eight other boats were converted to radar pickets under the MIGRAINE program: TIGRONE (SSR-419) and BURRFISH (SSR-312) received MIGRAINE I conversions, along with six thin-skinned Gato-class boats - POMPON (SS-267), RASHER (SS-269), RATON (SS-270), RAY (SS-271), REDFIN (SS-272), and ROCK (SS-274) - which received MIGRAINE III conversions.

	This engineering drawing shows the planned equipment layout in the air control center. (Courtesy of the National Archives)
This drawing shows REQUIN's MIGRAINE II conning tower from the side. (Courtesy of the National Archives)
This drawing shows REQUIN's stern, with the YE-3 fighter controller beacon (right) and the infamous SV-2 "Nodding Idiot". (Courtesy of the National Archives)

Life as a Radar Picket Submarine

Life for REQUIN as a radar picket was tough duty. Many of the normal fleet boats still in service stayed out for two to three months. REQUIN, because of her unique status as a radar picket (click on the link Life as a Picket to see photos of life at sea aboard REQUIN), would often stay out much longer, just coming into port to refuel and reprovision. Sometimes, REQUIN's skippers would be creative in keeping up the crew's morale. One skipper, Capt. David H. Green, devised a way of having steak barbecues while REQUIN was on the surface. Using a secret marinade recipe, he would have the grill, a 55 gallon drum cut in half and fitted with detachable legs, brought up on deck, steaks broken out of the ship's freezer and cooked on the grill.

Along with the boring times, picket duty did have its share of excitement. When the radar equipment worked, which was about half the time (the SV-2 radar, aka the "Nodding Idiot", was quite susceptible to flooding and shorting out, due to its location near the waterline on REQUIN's stern), it often worked well. During one picket mission, REQUIN's radar watched picked up a fast moving surface contact. They reported the contact as being on a heading of 090 and moving at 45 knots. The captain, thinking the men weren't seeing things right, ordered the watch to recheck and test the radar displays and antennas, thinking the contact's speed somewhat excessive. When the contact again was reported at the same speed and bearing, the  radarman on duty went to the bridge, reported that everything checked out and nothing was malfunctioning. When asked if he had been drinking alcohol, the radarman replied in the negative. As a result, a radio message was finally sent to the contact. The contact later turned out to be the new passenger liner SS UNITED STATES, which had just gone into service and was conducting speed runs during her maiden voyage. As the radar picket program was winding down, brought upon by the advent of miniaturized transistors, smaller radar systems which were capable of being fitted with aircraft, so on, REQUIN continued to serve as a picket until the end of the 1950s. In 1956, REQUIN achieved an "Outstanding" rating during an Operational Readiness Inspection, the first and possibly only, radar picket submarine to do so. Finally, with the advent of airborne early warning aircraft, such as the P2V Neptune and E-2 Hawkeye, the Navy decided to end the radar picket program in the late 1950s.