D.C. Harbor Police identified Daniel Shields, 14, of Wilton, Conn., yesterday as the youth who was missing and presumed drowned after falling from a powerboat into the Potomac River near Bolling Air Force Base Saturday evening.

Shields was sitting on the bow of the boat, outside the railing, with his feet dangling over the side when the 27-foot craft apparently struck the wake of a passing boat, police said.

According to a witness, Cornelius Van Cott of Silver Spring, the wake "flipped him Shields right up in the air like a pancake -- up and forward of the boat."

"He had been holding on to the railing and he reached back to try and get it, but he couldn't," said Patricia Van Cott, who was with her husband in a nearby boat.

The Van Cotts said it appeared the youth was struck by the bow of the boat as he fell into the water, and that the boat, which has a 260-horsepower engine, then passed over him.

The Van Cotts said they immediately dropped anchor to look for the youth.

"There were no bubbles; he never came up," said Cornelius Van Cott.

Shields, who was in the area as part of a Fourth of July vacation, was aboard the boat with John Paul of Northwest D.C., his son and two others, according to harbor policeman Larry Petropulos.

Paul apparently did not see the youth fall overboard, Petropulos said.

Paul could not be reached for comment yesterday.

According to Petropulos, riding outside the railing of a boat is a violation of federal and local safety regulations.

Shields was not wearing a life jacket at the time of the accident, but that was not required, Petropulos said, because laws require only that life jackets be aboard the craft.

Police said there is no speed limit for boats in the area where the accident occurred, at the Potomac's junction with the Anacostia River, between Bolling Air Force Base and Hains Point, and that the speed of craft in that area generally is not a problem.

Harbor police dragged the area for four hours Saturday and continued the search until dark yesterday