Early one recent morning on the docks of Newport, Rhode Island, the crew of the Swedish 12-meter yacht Sverige was taking last-minute instructions before heading offshore to practice racing for the America's Cup.

Suddenly an explosivesound erupted from the sleek boat, rocking her to the waterline. The Swedes casually turned around to assess the damage.

A running backstay, straining under tremendous pressure in its job of holding up the aluminum mast, had shredded.Stainless steele cable as thick as a finger was strewn on the deck.

The mast was still shaking. The Swedes shruggedand went to work rigging a new backstay. Fifteen minutes later that one exploded too.

Par for the course in pressure-riddled Newport on one of the busiest sailing weekends of the year.

Last weekend Newport, once a sad, tough little Navy town, was jammed, packed and pulsating with the rhythm of yachties and yacht hangers-on.

"Can you feel the pulseof this place? It's incredible," said Peggy Lord, a Washingtonian who was in town preparing to crew aboard Indian Summer in her seventh Newport-Bermuda race.

About 170 boats gathered for the start of the adventure last Friday, and their crews were surrounded by thousands more wives and husbands, children and friends jostling to see them off.

The night before departure every restaurant in the booming downtown was crammed to overflowing.

"I just called for a reservation at Christie's," said a hungry yachtsman at 9 one night."They told me there was a two-hour wait. Not just there. At every restaurant in Newport.

"I told them I've never waited two hours to get in a restaurant in New York. Then again, the lines go quick at Mcdonalds."

On race day morningthere was a Mcdonald's-size line at the checkout counter atJ.T. O'Connell's ship chandlery five minutes after the door opened at 8. A mild storm had sprung up overnight and the sailors were making sure they had everyting they needed.

These folks weren't buying extra potatoes. They were stocking up on flotation/foul-weather jackets, stainless steel yacht fittings elegant new deck shoes. They were spending hundreds of dollars at a clip.

"Funny," said a local observer, "the harder it blows the more nervous they get. And when these people get nervous, they spend money."

If sailing isthe music Newport dances to, money is the jingle. And it'sall doubletime.

Washingtonian Bucky Buchanan hove into town for the Bermuda race aboard former U. s. Rep. Ogden Reid's sloop Flyway. But Flyway had hit trouble on the way up off New London, running hard aground.

The impact damaged the drive shaft housing and the keel. Flyway limped into Newport at 8 a.m. Thursday under tow. The crew did not intend to miss the race.

The folks at Newport Offshore Shipyard responded with great speed. The boat was hauled by 9:30, the engine mounts rewelded and the shaft, vee drive and all the rigging checked. She was back in the water by 10 that night and on the course for the race the following morning.

In normal times the hubbub might have ended after the Bermuda fleet was off, but the very next day the first trials to select a defender for the America's Cup began. The same crowds that had headed out to see the ocean racers away Friday left the docks Saturday to watch Ted Turner and Dennis Connervie for the right to defend the Cup.

As the two yachts jockeyed for position at the starting line four miles offshore, a spectator fleet of 40 vessels pitched and rolled in thesea.

Then they were off. The yachts headed upwind to the first racing mark 2 1/2 miles away and behind them the fleet converged. It seemed chaotic, but it turns out there areformal, unspoken rules for the fleet to follow.

The purpose of the trials is for a committee from the New York YachtClub, which mounts the defense, to see who is fastest and best. So the committee boat, complete with its selection committee members decked out in blue blazers and straw hats, always is first.

Their boat is a massive blue motor yacht named; appropriately enough for these scions of industry, TheLion's Share.

As Lion's Share burbled off, the lesser folk fell in behind.

Over on Goat Island the third ring of Newport's sailing circus was developing, as officials of theObserver Singlehanded Transatlantic Race set up a 24-hour vigil, waiting for the first singlehanders to arrive in the 110-boat race from Plymouth, England. Each night they plotted the positions of the racers on the basis of computer printouts from satellite overflights of the 3,000-mile course.

And on Thames Street the crowds pitched and yawned from barroom to restaurant to wharf.

Big-time yachting in the Ocean State. I tell you, it's enough to make a fellow take up racquetball.