The U.S. buildup to next summer's yachting Olympics at Tallinn in the Soviet Union began in earnest Memorial Day weekend with the Olympic Pre-Trial Regatta at Newport, R.I.

Crews which did well in the six classes there not only received a psychological leg up for the long year to come, but the opportunity for solid financial assistance, too.

The U.S. Olympic Yachting Committee plans to spend $80,000 this year to get the hot U.S. sailors to Estonia, where the Tallinn course lies on an arm of the Baltic at the latitude of Hudson Bay.

The committee expects to make individual grants of $1,200 to 47 sailors who look good in the early season racing, and be able to ship about 22 boats for warm-up competition in European events and the Baltic XXXI regatta at Tallinn this August.

The Olympic series itself is scheduled in 1980, from July 21 through about Aug. 1. A ruthlessly simple method will be used to select the American representatives: There will be a seven-race elimination series next May at Newport, and a first-place finish wins the Olympic berth in each class, with an alternate also selected.

In the meantime, individual classes will run their own championships, select coaches which the USOC will finance, and generally try to see that the best contenders get the best opportunities to battle it out.

The goal - as always - is "a medal in every class." And as always, the United States is stronger in some types of boats than others.

The classes:

SOLING - The three-man Olympic keelboat class looks particularly hot this time, especially since Buddy Melges, the legendry Zenda, Wis., sailmaker and boatbuilder, appears to have signed on. Dr. Stuart Walker of Annapolis is the area favorite in a field that includes Vincent Bruns of San Diego, Robbie Haines of Coronado, Calif., and Dave Curtis of Marblehead, Mass., among many others.

Tstar - tthe venerable two-man keelboat has long been a magnet for heavyweights in this country, and the U.S. sailor who emerges from the Star wars will be well seeded at Tallinn. The shootout is expected to include Tom Blackaller of Alameda, Calif; Bill Buchan of Mercer Island, Wash.; Ding Schoonmaker of Seattle; Peter Wright of Chicago, and Santa Barbara's Bill Gerard.

FLYING DUTCHMAN - The Super-sophisticated 20-foot planing dinghy is troubled in this country by small fleets, but still sports a formidable list of talent. Pioneer Laser champ Dick Tillman of Satellite Beach, Fla., won the Dutchman series at Severn Sailing Association earlier this month, and will have plenty of company in races to come from Augie Diaz of Miami, Steve Taylor of New Haven, Gordy Bowers of Minnetonka, Minn., and others.

TORNADO - The Olympic catamaran class, like the Dutchman cats, suffers from a lack of depth, though individual performers are world class. Art and Joan Ellis, the husband-and-wife Fireball champions, are making a bid, as are Richard Loufek of Newport, Calif., iceboat ace Henry Bossett of Lake Kopatcong, N.J., and Randy Smyth of Newport, Calif.

470 - The 16-foot dinghy again is looking very powerful, and it is thought that whoever is selected will have a good shot at a Tallinn medal. The field includes Dave Ullman of Newport Beach, Calif., two-time world champion Skip Whyte and Steve Cucchiaro, both of Boston; Steve Benjamin of Oyster Bay, N.Y.; Chuck Millican of Sunapee, N.H., and Dave Kellog of Port Washington, N.Y.

FINN - Glory in the singlehanded Olympic class has pretty much eluded U.S. sailors since Peter Barrett won the silver madal in 1964, but this time things may be different. Six of the top 10 in the Finn Gold Cup last November were Americans, with John Bertram of San Francisco first and Carl Buchan, son of the Star Sailor, third. Ten local sailors signed on for the Pre-Trials: Andy Menkart of Bethesda; Midshipman Ted Houck and instructor Jim Kirk of the Naval Academy, and Dave Buemi, Paul Van Cleve, Jim Hahn, Craig Coltharp, Pat Healy, Martin McLaughlin and Peter Sokolosky, all of whom sail out of Annapolis.