There are plenty more bombs lost at sea than that. Practically all are ripe for the picking with today's deep sea salvage technology.
Here are a few:
10 MARCH 1956: A U.S. Air Force B-47 bomber carrying two capsules of nuclear materials for nuclear bombs, en route from MacDill AFB, Florida, to Europe, failed to meet its aerial refueling plane over the Mediterranean Sea. An extensive search failed to locate any traces of the missing aircraft or crew.
4 JUNE 1962: A nuclear test device atop a U.S. Thor rocket booster fell into the Pacific Ocean near Johnston Island after the rocket had to be destroyed. The test was part of the U.S.'s first high altitude atmospheric nuclear test attempt.
20 JUNE 1962: A second attempt to detonate a nuclear device in the atmosphere failed when a Thor booster was destroyed over Johnston Island. The nuclear device fell into the Pacific Ocean.
5 DECEMBER 1965: While the U.S. aircraft carrier USS Ticonderoga (CVA-14) steamed en route from bombing operations off Vietnam to the U.S. Navy base at Yokosuka, Japan, an A-4E attack jet loaded with a B-43 thermonuclear bomb rolled off the Number 2 elevator, and sank in 16,000 feet of water. The aircraft carrier was positioned about 70 miles from the Ryuku Islands and about 200 miles east of Okinawa. The bomb, aircraft and pilot were not recovered.
8-10 MARCH 1968: The K-219, a Soviet Golf II class (Project 629M) diesel-powered ballistic missile submarine armed with three nuclear SS-N-5 missiles, sank in the Pacific, about 750 miles northwest of the Island of Oahu, Hawaii. The submarine possibly also carried two nuclear torpedoes.
27 MAY 1968: The U.S. nuclear-powered submarine USS Scorpion (SSN-589) sank about 400 miles southwest of the Azores, killing all 99 men on board. The submarine was powered by one nuclear reactor and carried two nuclear-armed ASTOR torpedoes.
12 APRIL 1970: The K-8, a Soviet November class (Project 627A) nuclear-powered attack submarine, sank in the Atlantic Ocean 300 miles northwest of Spain. The submarine was powered by two nuclear reactors and carried two nuclear torpedoes.
6 OCTOBER 1986: The K-219, a Soviet Yankee class (Project 667A) nuclear-powered ballistic missile submarine armed with 16 SS-N-6 missiles (two warheads each) and probably also two nuclear torpedoes, sank 600 miles northeast of Bermuda. It was powered by two nuclear reactors and 34 nuclear warheads were estimated to be on board.
7 APRIL 1989: The K-278 Komsomolets, the Soviet Mike class (Project 685) nuclear-powered attack submarine, sank off northern Norway following on board fires and explosions. The submarine was powered by one nuclear reactor and carried two nuclear torpedoes.
28 July 1957
A C-124 Globemaster transporting three nuclear weapons and a nuclear capsule from Dover Air Force Base in Delaware to Europe experienced loss of power in two engines. The crew jettisoned two of the weapons somewhere east of Rehobeth, Del., and Cape May/Wildwood, New Jersey. A search for the weapons was unsuccessful and it is a fair assumption that they still lie at the bottom of the ocean.
22 January 1968
A B-52 crashed 7 miles south of Thule Air Force Base in Greenland, scattering the radioactive fragments of three hydrogen bombs over the terrain and dropping one bomb into the sea after a fire broke out in the navigator's compartment. Contaminated ice and airplane debris were sent back to the U.S., with the bomb fragments going back to the manufacturer in Amarillo, Texas. The incident outraged the people of Denmark (which owned Greenland at the time, and which prohibits nuclear weapons over its territory) and led to massive anti-U.S. demonstrations. One of the warheads was reportedly recovered by Navy Seals and Seabees in 1979, but a recent (August 2000) report suggests that in fact it may still be lying at the bottom of Baffin Bay.
1954
An experimental sodium-cooled reactor utilized aboard the USS Seawolf, the U.S.'s second nuclear submarine, was scuttled in 9,000 feet of water off the Delawre/Maryland coast. The reactor was plagued by persistent leaks in its steam system (caused by the corrosive nature of the sodium) and was later replaced with a more conventional model. The reactor is estimated to have contained 33,000 curies of radioactivity and is likely the largest single radioactive object ever dumped deliberately into the ocean. Subsequent attempts to locate the reactor proved to be futile.
September 25, 1959, Off Whidbey Island, Washington
A U.S. Navy P-5M aircraft carrying an unarmed nuclear depth charge without its fissile core crashed into Puget Sound near Whidbey Island, Washington. The weapon was never recovered.
FEBRUARY 1991, Off Somalia
In February 1991, the Pentagon sent out an emergency message: three "Broken Arrows," or lost nuclear weapons were jettisoned in the Indian Ocean by a U.S. Air Force B-52, which had caught fire en route from Diego Garcia. The three nukes landed in the shallow waters off the Somali coast. In May 1991, they were allegedly recovered by mercenaries.