Soviet planes and a warship maneuvered close to a U.S. cruiser and a destroyer as they sailed the Black Sea within six miles of the Soviet coast last week, Defense Department officials said yesterday. They added that the Soviets broke precedent by publicly protesting the transit, which the United States says was an "innocent passage" and not intended to make a diplomatic point or be provocative.

The U.S. officials said the cruiser Yorktown and the destroyer Caron did nothing markedly different in their transit last week along the southern coast of Crimea than Navy ships had done in November 1984 in sailing inside the 12-mile territorial limit claimed by the Soviet Union.

Pentagon officials said the Soviet government did not publicly protest the 1984 transit, which U.S. officials also described as an "innocent passage."

This time, however, Soviet leader Mikhail Gorbachev filed a diplomatic protest with the U.S. Embassy in Moscow and informed Tass, the government news agency. Reagan administration officials theorized that the protest may mark a decision by the new Soviet leadership to portray the Reagan administration as bellicose whenever U.S. military maneuvers offer the chance.

The next opportunity could occur soon in the Mediterranean, where three U.S. aircraft carriers -- the Coral Sea, the Saratoga and the America -- are converging under the eyes of Soviet ships.

The America entered the Mediterranean yesterday to relieve the Saratoga, which is scheduled to sail home. But Defense Department officials said it will be held in the area for more than a week to provide extra firepower to discourage any Libyan or Soviet military response to the expected crossing of the line drawn across the Gulf of Sidra by Libya's Col. Muammar Qaddafi.

Sources said that Gen. Bernard W. Rogers, commander of European forces, did not want to cross Qaddafi's claimed "line of death" at 32 degrees 30 minutes north latitude, taking in most of the Gulf of Sidra, until all three carriers were in the region.

Pentagon officials said in a statement Tuesday that the Black Sea transit, which last Thursday came within six miles of the Crimean coast, was "neither 'defiant' nor 'provocative,' as asserted by the Soviet government. It was simply an exercise of the right of innocent passage. International law has long recognized the right of ships of all nations to engage in innocent passage through a country's territorial seas without prior notification to, or permission of, that country. Although exercise of this right is not dependent on the legislation of the coastal state, we note that this transit was, to the best of our knowledge, consistent with relevant Soviet law."

The Soviets used a Krivak destroyer to trail the Yorktown and the Caron, Pentagon officials said, and had military aircraft fly over the ships. The two U.S. warships have electronic gear that can intercept radar signals and voice communications; it is standard procedure on such transits to use such gear to try to determine if new radars have been deployed on shore, and to check on the state of readiness of Soviet forces. However, Pentagon officials said this was not the primary mission of the Black Sea transit, which was intended to reassert the right of innocent passage in those waters.