It was a most incongruous sight sitting there in the middle of the Potomac River: a small ferry boat, decks awash, with two fertilizer trucks perched so precariously that waves lapped at their lug nuts.

After almost three decades of successfully plying the 300 yards between Maryland and Virginia, the Gen. Jubal Early had swamped short of the opposite shore.

In the farm country 25 miles upriver from Washington the proprietors of White's Ferry, a small riverside community, usually welcome the public onto their private property to buy cold beer, rent a row boat or ride the Gen. Early.

But yesterday you couldn't make a phone call at the shore, the gate was drawn across the entrance, and a kid in mirrored sunglasses said he was getting paid by the hour "to keep the gawkers away."

"The captain doesn't want to make a big deal about it," he said, shooting off a trickle of curious visitors and glaring at the Piper Cub orbiting overhead.

Wednesday morning the owners of the ferry had the misfortune to load on from the Virginia side of the Potomac two dump trucks that were taking 15 to 20 tons of lime to corn and soybean fields on the other side of the river. The passage normally takes about four minutes. As of late yesterday afternoon the voyage was still under way.

It was around 9 a.m. and less than half the distance to the bare sycamores on the Maryland shore when the port side of the ferry, a 60-foot boat built in 1954 with a shallow vee-shaped hull, began to swamp.

"It exceeded its rate limits apparently," said Lt. John Repass of the Poolesville Fire Department who responded to a telephone SOS with their 15-foot river rescue boat.

The fire department arrived to find that the two truck drivers and the operator had taken the push-boat which noses the ferry across the river back to the Virginia side and did not need to be rescued.

"It's sort of half swamped," Repass said. "It's resting on the bottom in about 10 feet of water. It probably would have flipped if it had been in deeper water."

Since the mishap, owner Malcom Brown and crews have been running out to the ferry in a stiff, welding vents shut and pumping water out of the hold in an attempt to refloat it. "I imagine you'll find they might be easier to get along with if they make some progress," said a farmer who had been helping out.

The ferry provides the only crossing along a 45-mile stretch of the Potomac from Chain Bridge to Point of Rocks, Md., and it can cut 20 miles on a trip from Maryland to Virginia. The Jubal Early is a "captive ferry" which is guided by a cable that runs along the river bed. It broke lose a few years ago, during a time of high water as 81-year-old Carroll Chiswell remembers it.

"It floated all the way down to Seneca," Chiswell recalled. "Whoever was on it was a-cussin' all the way. Said he was going to hell." The Jubal Early was towed to its duty none the worse for wear after the joyride.

Ferries have crossed this spot of the Potomac for the more than 150 years, and the area is rich in Civil War tradition. It was near White's Ferry that Gen. Robert E. Lee led his troops across the Potomac enroute to Gettysburg in September 1862. The Gen. Jubal Early herself is named after a Confederate general, who marched on Washington and then beat a retreat through the Maryland woods.