On 13 April 1986, USS GRAYBACK (SS/SSG/LPSS-574), stripped down to an empty shell and painted bright orange, was towed out of Subic Bay in the Philippines and sunk in the South China Sea as a target for a training exercise. It was an anticlimactic end for one of the Navy’s most unusual and versatile submarines.

GRAYBACK was originally intended to be a fast attack boat; she was already under construction when the Navy decided to redesign her as a platform for launching REGULUS guided missiles. Builders at Mare Island Naval Shipyard in California cut the sub in half and inserted a new fifty-foot section of hull into the gap; they also added a missile hangar to GRAYBACK’s foredeck, turning her into one of the strangest-looking subs the Navy has ever constructed. By the time she was finished, GRAYBACK was the largest diesel-powered sub in the world and, in fact, “the largest—at that time—underwater craft in terms of displacement tonnage,” according to Submarine Base New London’s newspaper, the Dolphin. She was also the first purpose-built missile-firing sub, demonstrating her capabilities in September of 1958 with the first submarine launch of a REGULUS II missile. Writer Ralph Harvey dubbed the boat “the sub with the thousand-mile punch” and described the missile launch this way, just a few days before it actually happened: “A steel door will open in its bulbous snout and a vicious, bullet-like missile with razor stubs for wings will slide out and elevate. Instantly, the missile’s jet engine will begin to screech, ripping yards of foam from the sea surface.” Unfortunately for GRAYBACK, POLARIS soon became the Navy’s favored missile and the sub was decommissioned in 1964.

GRAYBACK’s second life began just a few years later when the Navy determined that there was a need for a submarine personnel carrier. So back to Mare Island GRAYBACK went. Workers there lengthened her sail, added two auxiliary tanks (and 12 feet of length) to the forward end of her engine room, and converted her missile hangars into space for 60 troops and several SEAL Swimmer Delivery Vehicles, as well as a decompression chamber. It was in this new configuration that GRAYBACK, in 1972, undertook what was at the time a highly classified mission, code named Operation Thunderhead, whose goal was to rescue two airmen who were being held captive in North Vietnam. Although the mission was ultimately unsuccessful and caused the death of one SEAL, GRAYBACK and her crew performed admirably. It was the last attempt the United States would make during the war to rescue American POWs.

In an article written for the Dolphin in 1984, GRAYBACK Sailor Winton Worth expressed his views on his vessel, sentiments with which many of his shipmates would certainly have agreed: “When Grayback is gone they ought to bring back another that can do the same things. If someone asks me to serve on it, I will. And if no one asks me, I’ll ask them.”