The Harvard heavyweight crew enters a new league this summer, -- international and club competition, including the Vesper Boat Club of Philadelphia.

A heavy schedule of rowing during the next three months should determine how well the Crimson compares with the nation's best. Crew coach Harry Parker will only say "we're looking ahead," but "looking ahead" in this case means the oarsmen at Newell Boathouse have their eyes on next year's Olympics at Mexico City.

There is no definite racing schedule yet, since much depends on whether Harvard can win in early July and keep on winning.

The crucial hurdle will be the trials for the Pan American Games, to be held at Orchard Beach Lagoon in Pelham, N.Y., June 30 and July 1.

The winner at the trials will represent the United States at the Pan Am Games in Winnipeg, Canada, at the beginning of August.

"If the Sprints were any--indication, and if we can recover from exams, I think we'll go down to the Pan Am trials with a good chance of winning," Parker said.

Entrants at the Orchard Beach trials have not been announced yet, but likely competition includes Northeastern and Penn (beaten decisively at the Sprints) and from the West Coast, U.C.L.A. and the University of Washington. Wisconsin is going to Henley instead.

Parker rates the Coast crews weaker than competition his eight has already faced this season.

But Vesper Boat Club is something else again. Vesper edged the Crimson in the 1964 Olympic trials, and went on to Tokyo. Parker says there is "no guarantee" that Vesper -- with an almost totally new roster -- is as strong this year, but last week its senior eight scored an impressive two-length victory over the New York Athletic Club shell. NYAC is also rated strongly, and will probably enter the trials at Orchard Beach.

If the Harvard eight loses in the Pan Am trials, plans call for splitting into fours and entering the small boats competition. Some of the junior varsity oarsmen will be competing in fours as well.

Before the Pan Am trials, Harvard will have to face its grueling four-mile Yale race at New London, Conn., June 17. "The Boat Race," as it is known to the more arrogant crew buffs in New Haven and Cambridge, is the oldest intercollegiate sports contest in America.

Little Doubt

There seems to be little doubt that Harvard's varsity will win the 102nd rerun this June. The freshmen also appear strong favorites, but the junior varsity may encounter serious problems with Yale in its three-mile contest. Harvard placed behind the Elis at the Sprints in May.

Still Tentative

After the trials, all is still tentative. If Harvard wins everything, the schedule heads: "The Pan Am Games at Winnepeg, August 2-5; the North American Championships at St. Catharines, Ontario, August 10-13; and the National Championships at Orchard Beach in New York, August 26-27, to decide which U.S. crew will compete at the World Championships in Vichy, France, September 8-10.

If the Harvard eight can win at the Pan Am trials, there is more than a good chance that it will triumph at the Winnipeg games. At the North American Championships, European competition will be entering. Strongest rivals there will be the high-stroking Ratzeburg Boat Club, from West Germany, and an East German crew.