The entry from the Potomac Boat Club of Washington, D.C., an uncoxed four, will make its debut in the Royal Henley Regatta Friday.

The Potomac crew includes two men who may be the oldest competirors in the regatta. Thomas Charlton, 42, an Alexandria, Va., engineer, was a member of the U.S. eight that won the gold medal at the 1956 Melbourne Olympics. In the same rowing generation is TownsendSwayze, 39, of Washington, D.C., who captained the Harvard crew that won the Grand Challenge Cup here in 1959.

The crew has made a point of noting that its oldest member Charlton, started rowing in 1949, five years before its youngest member. Brian Keene of Washington, was born. The fourth member of the crew, whose average age is 33, is 28-year-old Robert Blakely of Arlington, Va.

Strong gusty winds ensured that times in today's 74 races were well below par. Most times for the eights were more than one minute slower than various records and one and two-man entries were usually two minutes slower.

The wind provided the olfactory highlight of the afternoon, blowing the pungent aroma of roasting hops from the local Henley Brewery over the course.

Three of the six crews entered in Henley's premier event, the Grand Challenge Cup, are American, and each has a reasonable claim to be the U.S. college eight.

Cornell won the IRA championship, Harvard the Eastern Sprints and Washington the Pacific Eight and San Diego competitions. The only meetings between any of the three were in the Eastern Sprints, in which Cornell placed third, and last weekend's Nottingham Regatta, in which Washington finished ahead of Harvard.

Now, on foreign waters, the argument may be settled once and for all. At least to the satisfaction of the winner.

No one is arrogant enough to assume that the Grand Challenge winner will necessarily be one of the three U.S. crews.

Strong resistance will come from Leander and Thames Tradesmen, the Henley alias of the British national eight.None of its present members, however, was in the crew that won the silver medal at Montreal.

A strong Oxford crew includes two members of the U.S. 1974 world championship eight.Al Shealy and Ken Brown. The sixth entry in the top event is Garda Siochana, the Irish police.

Most Americans had no chance to show their strength on the Regatta's first day today. The three U.S. entries in the Wyfold Cup for uncoxed fours - Potomac, Harvard and California, drew byesinto the last 16. Seven other U.S. entries, including the Grand Challenge hopefuls, were also idle today.

St. Anthony's Hall, Williams College and Washington's lightweight varsity eight won easily in heats of the Thames Cup.

Perhaps the most unexpected loss today was that suffered by Wayne State's Brian Brennen and Gary Wojdla, the IRA national champions, in the Silver Goblets pair-oared event. They led for most of the 1 mile and 550 yards but lost by half a length to the Lady Victoria pair.

But Dick Cashin and Tim Mickelson, other members of the 1974 world champions, won their Silver Goblets heat by three-quarters ofa length.