The sands of Scusset Beach became a footnote in Marine Corps history today when the 36th Marine Amphibious Unit took the beach without firing a shot.

The only unanticipated factor in the cold weather war games which began here today with a Navy-Marine amphibious landing was the size of the crowd of civilian spectators.

Lance Cpl. David Arbuckle was among the first Marines to hit the beach. They jumped out of the amphibious armored vehicle (amtrac), whose camouflage made them look like giant moving Rorschach blots, rifles at the ready.

"Wow! What are all those people doing here?" Arbuckle asked as he faced about 1,000 onlookers who had waited more than an hour in 25-degree weather made bitter by a strong wind to watch the assault on Scusset Beach. "I didn't expect to step out of the Amtrac and see so many folks," Arbuckle said.

"As long as there was such a large crowd, I'm sure as hell glad they weren't hostile," Navy Capt. A. J. Paulson, who commanded the combined task force, joked.

They weren't. War games apparently are back in fashion. "Take that, ayatollah!" onlooker John Billings yelled as the first helicopters streamed over the surf toward the beach. Marine and Navy officers remarked they were surprised by the number of reporters -- close to 50 -- who turned out.

The landing was planned last July, long before Americans were taken hostage in Iran or the Soviet Union had invaded Afghanistan. But for the chilled crowd the glimpse of American military strength was a treat.

In the absence of a belligerent enemy, the biggest obstacle the Marines faced at Scusset was the terrain -- not how to get over it, but how to avoid destroying it.

To limit damage to the beach, the landing was what one Marine officer called "highly artificial."

The Amtracs came ashore from Navy ships in Cape Cod Bay in waves covering the entire landing area, but after the 22 men packed into each one had clambered onto shore, the assault waves became a single file parade with all the Amtracs exiting the beach over the same paths.

The rifleman were allowed to skirmish through the dunes, alternately running forward and then flinging themselves to the ground. As they went through their paces, they skillfully avoided the reporters, photographers and Marine brass at whose feet a skirmisher's head would from time to time appear.

The Marines secured the perimeter around the beach parking lot, its shuttered snack bar, shower rooms and toilets, but the Corps of Engineers was enraged.

They had a problem perhaps unique in amphibious landing history -- not to mention war correspondence: media representatives were trampling the sand dunes.

Bill Norman, a park ranger working for the Corps of Engineers, said the dunes through which the Marines were maneuvering are ecologically fragile. "If the beach grass is crushed, it won't grow back," he explained. The Corps of Engineers owns Scusset Beach.

"I don't give a damn about the operations. I'm trying to save the dunes," one of Norman's frustrated aides said.

It was a losing fight. The dunes were studded with Marines advancing around reporters while reporters ignored the engineers who were stepping over and around prone Marines.

Capt. Paulson pointed out that while most amphibious exercises take place in warmer weather, cold weather operations are useful as tests of Navy-Marine ability to make an amphibious land, any time, any place.

"Frankly, we were hoping for a lot of snow," Paulson said.

In the cold weather an exercise tests how long the boat crews and helicopter flight deck crews can work without needing a break. Half the 1,800-man landing force went ashore by helicopter from the USS Saipan and the USS Pponce.

After the landing, the Second Marine Division, which is billeted at Camp Lejeune, N.C., drove along public roads, over the Sagimore Bridge, to Camp Edwards, near Sandwich for three days of war games.

The games include live artillery and mortar fire practice and some mock battles with the bad guys, portrayed by the 1st Battalion 25th Marines.

Paulson and the Marine commander here, Col. Peter L. Cacace, pronounced themselves satisfied that the landing was carried out almost exactly as scheduled.

The spectators liked it, too. "This is dynamite," one woman said as she watched the landing begin "and right on time, too," she said.