Rescue worker Neal Walker is sure of one thing: The river has no respect for anybody.

He is describing the Potomac, a river he grew up next to and has learned to treat with caution. His warning holds particularly true for the 11-mile stretch of white water from Great Falls to Chain Bridge, the area where people most often run into trouble.

Walker has been a member of the Cabin John Volunteer Fire Department for 17 years, and during that time he has participated in more than 50 rescues along the river near Great Falls. Already this year, five persons have been pulled from the rocks and water in the stretch below the falls.

There have been no accidental deaths thus far this year. But if people could see the bodies rescue teams pull out of the water, Walker said, "they would think twice about going in the river."

Some boaters have to be rescued by air from the rocky river. A U.S. Park Police helicopter several days ago plucked three young men from a small island where they had spent the night after their canoe overturned in the turbulent water.

One canoeist, David Dickson, 24, of Potomac, said of the accident: "Usually we canoe out there in the summer when the water isn't so high. . . . Last night . . . the current just took us faster than normal because the water is higher and swifter."

Despite renewed efforts each spring by the National Park rangers and the Park Police to keep swimmers and inexperienced boaters out of the water and hikers and fishermen away from the river's most treacherous rocks, swimmers continue to be pulled under, boats continue to capsize, and hikers and fishermen continue to fall victim to the fierce current.

Kayakers regularly practice in several stretches of the river, and even help out in rescue operations. Such experienced boaters "cause us very few problems," said Park Ranger David Jones.

The cliffs above the river, particularly at Carderock, are popular with climbers. One Gaithersburg youth, rescued by a team of rope and rigging specialists on Feb. 21, said he had fallen off the rocks near the Billy Goat Trail before he knew what was happening to him.

"One moment I was rappelling," said Martin Peter Ferrero, 18. "Then my rope just kind of came with me." The firefighter rescue squad had to haul him up a 40-foot cliff. He was then taken to Suburban Hospital and treated for a skull fracture.

For hikers and bikers who frequent the canal towpath on warm weekends, the sight of rescue vehicles is not uncommon.

As the weather turns warmer, Cabin John firefighters and Park rangers know they are going to be called to the river more frequently.

"When we get an early start like this, it usually means we're going to get a busy summer down there," said Sgt. Robert Hunter of Cabin John.

Park Service records show four drownings in 1980, five in l98l and five in l982. In some previous years, the number of drownings has been as high as 13.

"We average about seven drownings a year," said Jones. "People continue to go in the river. It does get frustrating."

Rescue workers say there are four chief trouble spots along the 11-mile white-water stretch: Great Falls; the stretch near the Old Angler's Inn; Carderock; and Little Falls. In all four places, the current is swift and there is easy access to the water.

Park Service officials say the most serious accidents tend to involve swimmers, waders and inexperienced boaters. In recent years, most drowning victims have been young men in their teens and early twenties.

"The Potomac River is unpredicable," says Cabin John fire chief Don Money. "The water is calm on top. The current is underneath."

Not all drownings occur in fast-moving water. Neal Walker said that a patch of cold water next to warm water often can give even good swimmers bad and sudden cramps. This sometimes has been the case in "Catfish Hole," a relatively calm pool just below Great Falls. "We've lost a lot of kids in that area," Walker said.

Pulling drowning people out of the river is dangerous work and sometimes rescue workers have had to be rescued themselves in the middle of an operation. Some voice some resentment about having to respond to accidents that in most cases could have been avoided had the victim used common sense.

"People know about the river," says Cabin John firefighter Mark Tennyson. "It's frustrating because it doesn't have to happen."

"It's different from fighting a fire," his coworker Doug Arnold said. "When we run down the river on these rescues, it's just stupidity."

But despite the posted signs that warn of the water's danger and the laws that prohibit swimming, officials expect that a certain number of people will disregard them again this summer.

Hunter says that for many people the river is a source of excitement, "and everybody wants to have a little bit of adventure in his life."