A FEW DAYS AGO Art Conners did something the prowling German submarines of World War II couldn't do.

He sank the Liberty Ship Edgar E. Clark 30 miles off Virginia Beach. Four minutes and 20 seconds after he turned the handle of a little detonating device called a hellbox, the venerable Clark, its bottom ripped to shreds, slipped beneath the waves of the Atlantic.

It rests today in 115 feet of water, and if things are going as planned tiny organisms already are attaching themselves to the Clark's scabrous old hull. Perhaps a few sea bass and tautog have move into the dark chambers of the ship's ruptured belly. That's what everyone is hoping for.

The Clark was the sixth and last Liberty Ship to be sunk off the Virginia coast in the last three years. The ships, part of the mothball fleet tied up in the James River since World War II, will serve as artificial fishing reefs.

The Virginia Marine Resources Commission of Newport News has been in charge of the project. Mike Meler, a 28-year-old fisheries reef manager with VRMC, has overall responsibility for seeing that things go well.

No question about it, the sinking of the Clark went well.

Six hundred pounds of C-4 plastic explosives and 10 bangalor torpedoes attached to the sides and bottom of the 440-foot ship assured a spectacular explosion and the ship settled to the exact spot on the Continental Shelf that Meier had marked with an "X" on his map.

As zero hour approached last week, the Coast Guard sealed off the area. Boats and planes were shunted out and radio communication was shut off to prevent a wandering electrical signal from prematurely setting off the charges in the Clark.

The explosives had been placed the day before by Conners and others in the Navy's Harbor Clearance Unit from Little Creek Amphibious Base. The 80-passenger Sea Sport, a headboat out of Rudee Inlet, circled the old ship slowly while Conners and his men dropped a raft over the side and paddled to the ladder of the Clark for the last time.

It took them nearly an hour to arm the exlosives, reel out a floating firing line to the Sea Sport and drop anchor on the Clark while a tug towed it over a selected spot on the ocean floor.

The anchor took hold. The tug straightened the towing line. The Clark swung around in line with the other ships that had been sunk, then sat heavy, mute and dumb in the mild chop of the Atlantic.

Flares went up. Someone shouted the traditional warning, "Fire in the hold," paused a few seconds, then cried again, louder, "Fire in the hold!" Conners pushed the plunger.

Thee sides of the Clark actually bulged with the force of the blast. Orange fire and gray smoke tumbled skyward. Observers on the Sea Sport, slightly more than the length of a football field away, felt a dull blow to the stomach. Shrapnel splashed in the ocean.

The stern of the Clark began to settle slowly, like a fat man easing himself into a bathtub.The bow tilted upward and within minutes the Liberty Ship was gone forever, although water continued to churn and boil from air trapped in the hull for more than five minutes.

Lined up in a southerly direction with the Clark are three other Liberty. Ships sunk earlier in what locals call the Triangle Wreck area.

The Clark, said Meier, was one of eight Liberty Ships built formfrom discarded aircraft and tank parts.

"It carried everything from fuel to supplies to war brides during World War II. Someone called these old Liberty Ships the Model As and DC-3s of the sea. I think they were probably right."

With its superstructure cut to second deck level and all gear removed, however, the romance was gone and the Clark looked like nothing so much as a big rusty bathtub wallowing behind the tug that pulled it to the open sea.

Pigeons by the thousands had roosted in its cavernous recesses when it was mothballed on the James River, but the insides had been flushed out with chemicals and water to guard against pollution.

The sunken ships make good artificial reefs that attract a rich diversity of fish, and they're expected to last close to 150 years, Meier said.

North Carolina, Georgia, South Carolina, Maryland, Florida, Texas and California all have artificial reef programs. Texas, naturally, has the largest.

"A lot of the Atlantic has a shifty botton" said Meier. "Sunken ships, old tires, anything like that will give crustaceans a place to live. The small fish move in behind them. Then the large fish follow the small fish."

If Meier had his way, he'd drop the ships closer to shore, not 30 to 35 miles out in the ocean.

"But I can understand the opposition to having them closer," he said.

"You've got to realize there's a lot of valuable space in a small area just off the month of the Cheaspeake Bay. There are merchant shipping lanes, submarine lanes, ordnance disposal areas and of course the fishing fleets. The menhaden fishing grounds just off the coast, for instance, are one of the most productive in the world."

So commercial fishermen afraid of snagging sunken ships in nets and merchant shippers who are alarmed at the prospect of running down small fishing boats in the shipping lanes have been successful in getting the artificial reefs moved farther offshore than Meier would like.

The first ship sunk off Wachapreague already is covered with mussels and flounder pulled from wrecks off North Carolina have ripe ovaries, which suggests that they have chosen the wrecks for a spawning ground.

The clark, along with its sister ships off Virginia Beach, will show up now on all new charts. And since North Catolina fisherman have had some trouble locating their wrecks, Meier hopes to mark Virginia's ship reef with buoys.