Cliches become great when they are completely correct, like the one that compares watching a yacht race to watching grass grow.

Yet I would rather watch the 12-meter yachts race at Newport this summer than watch grass grow, despite the fact that yacht-watching is boring, seasick-making and terribly expensive.

The secret to yacht-watching at this year's America's Cup is not the boats but the shore - Newport. The great cliche was correctly written, repeated far too many times, but it failed to take into account that after the racing is over, one return to Newport, R.I.

Are you a sailor? No? Then you may never know of the excellences of this thoroughly excellent place. You may never travel down the wonderful sea road past Fort Adams, past the crazy Maxwell's Folly, a mansion perched on a rock like an elephant on an egg, past the sweet smelling lawns and stone follies of American magnates, past Beavertail Point, spread like a shining spear on the blue sea, out to the playground of the 12-meter yachts.

The America's Cup is coming, late this summer, and thousands of people will crowd into town for two weeks at the beginning of September to watch what promies to be the greatest 12-meter show ever staged by the doughty New York Yacht Club.

Watching yacht races is only fun for two types: Those who have faithfully followed development of the 12-meter racing sloop in Cup competition over the years and those who simply love beautiful boats.

For everyone else the magnet in Newport is the place and the yachting people who come there. Twelve-meter yachting people are a special brand of rich; they're fit and tanned and wear faded clothes; they talk about esoteric things like the weight of a boron fiber spinnaker pole. You can tell they are a different breed of rich when they step aboard exquisitely maintained yachts at the best marina spots around Newport - they are living aboard their yachts to save hotel money.

The pleasures of Newport Cup time are not all visual. There is a great deal of seafood eating and prodigious drinking; this drinking is rich falk's drinking, and never gets out of hand. In this Newport has changed - all the seedy, sloppy, salty bars with 20-cent beers and normal humans have been steamrollered by authentic chic and $1.45 beers designed to attract a better clientele.

This drinking goes on and on. Each America's Cup seems to decide on a new watering place and in this place, with enough time and attention, you can see all the greats of the 12-meter world and the New York Yacht Club. This year there will be other greats from Australia (these are always large and identically handsome) and sailing greats from Sweden (never before seen n quantity at Newport); greats from Great Britain (look for thin noses and buttons) and perhaps the greatest, the sailing greats of France, led by the marvelous Baron Marcel Bich.

All of these sailing people will be discussing one topic. No one knows what it is at this point, but for convenience let's call it the weight of a boron fiber spinnaker pole.

After three or four hours of steady, rapid conversation on this subject, the 12-meter crews will disappear for dinner at whatever mansion their equipage has rented for the summer. The French will stay and glow far into the purple dusk and the starlit Newport night.

This behavior continues for at least a month before serious racing begins, while trials are held on the bay to select a challenger for the Cup and on the other side, a defender.

Walking back from one of these watering places through the narrow streets of the city, the city of Henry Wadsworth Longfellow, Henry James, Julia Ward Howe, Stanford White, to name a few of the intellectual stars, one feels full of happiness.

Newport has more 18th Century houses still intact than any city in America, and thanks to the efforts of Mrs. Angier Biddle Duke (tobacco), most are being beautifully restored.

These houses pour their grace and age into the dark streets; below, the harbor rests, glittering; black shadows of yachts swing behind anchlor chains, the tide is retreating, sucking at weathered piers, flowing to the dark heart of the ocean.

I once had a small sloop anchored at Newport at Cup time. From the cockpit I had a vantage of the town, tree-lined and busy, and an excellent view of the Newport Shipyard and William & Manchester, the two big yacht yards where the racing boats are berthed.

These yachts are kept in the highest state of perfection; there is continual work being done, the sound of the hammer, the saw, the block and tackle. What could be more cheerful than sitting beneath a fluttering pennant on a little boat, watching experts at work on the 12 meters?

It will be the same again his summer. There will be more 12-meter yachts in one place than at any time since World War II, and the fresh excitement of the new entrant into international Cup competition, the Swedish yacht Sverige.

The American entries represent the range of U.S. sailing talent, coast to coast, as well as the range of U.S. millions, for a 12-meter campaign is said to cost over $1 million.

The 1974 defender, the pure white Courageous, is to be sailed by Atlantan Ted Turner, who faithfully and cheerfully sailed the red-hulled, luckless Mariner in 1974 to last place in everyone's rating books. The boat never showed the slightest speed; Turner, who has gained most of the world's best known yachting trophies, and now also owns the Atlanta Braves baseball team, is back to try again.

Intrepid, the "breakthrough" boat, the fastest 12-meter ever built, some say, the successful defender in 1967 and 1970 and loser by a hair to Courageous in the 1974 trials, is to be campaigned again by Gerry Driscoll, a West Coast helmsman and boat builder.

The early favorite for U.S. defender must be Enterprise, a new aluminum boat designed by Olin Stephens, the Bernini of yacht design, who also designed Intrepid and Courageous and almost every other defender since 1937. On past form, with sailmaker and engineer Lowell North at the helm, ex-Intrepid sail trimmer John Marshall on deck and a large number of dollars within reach, Enterprise should win.

The other new U.S. boat is Independence, designed, owned and sailed by Boston sailmaker Ted Hood, North's arch business rival. Hood designed the fast but unsuccessful Nefertiti for the 1964 Cup and a score of top ocean racers. If Hood loses to North in the trials for selection, he will also lose his unofficial rank as the king of world sailmakers.

The only way to rate the foreign challengers, more numerous than ever, is by the tenuous yardstick of the Australian Gretel II, which narrowly lost to Intrepid in the 1970 contest.

Gretel II, altered by designer Alan Payne for 1977, is half of the Australian entry. The other is a new boat, owned by the unquenchable land developer Alan Bond, who brought Southern Cross to Newport four years ago, straight into a trouncing at the hands of Couageous. Australia is designed by Ben Lexcen, a young Australian dinghy sailor who changed his name legally from Bob Miller. As Miller, Lexcen designed Southern Cross. Australia is considered slightly faster than Gretel II - which means not fast enough.