SUMMERTIME : BEACHES : Over the mountains, across the sand to the ocean they go, even if they are landlocked Valley dwellers. They all have their favorites, too . . . best surf . . . best diving . . . or maybe just best for hanging out.

Sea breezes may stop short at the Santa Monica Mountains but, come summer, San Fernando Valley dwellers still catch the allure, if not the scent, of the ocean.

Valley teen-agers, for example, have long made Zuma Beach their hangout. One of Southern California’s oldest surf shops is Val Surf & Sport. And Willie Morris, a top-ranked professional surfer in the mid-1980s, hailed from the decidedly dry Woodland Hills.

Landlocked as it may be, the Valley is closer to the beach than many other areas of the city. Malibu and Zuma are just a half-hour’s drive from Van Nuys. A pleasant cruise over Topanga Canyon Boulevard lands West Valley residents at the coast in less time.

What follows is a quick guide to Valley-convenient beaches, beginning at the intersection of Topanga Canyon Boulevard and Pacific Coast Highway and moving north.

BEST SURFING: Beach at Malibu Point and Topanga State Beach

Few surfing spots on the planet boast the orderly, machine-perfect waves that curl across this point toward the Malibu Pier. This is a hallowed spot, the former stomping grounds of the legendary 1960s surfer Mickey Dora.

Surfrider is actually divided into three areas. The northernmost area, or third point, offers a variety of waves. Second point runs fast and furious, well-suited for the acrobatics of surfers who prefer agile short boards. At first point, long-boarders can tuck into a trim and ride all the way to the sand.

This beach also can provide the worst surfing. On a warm summer day when a south swell gets cranking, the waves can be as crowded as Santa Monica Freeway at rush hour. And the surfers are surly.

So beginners are advised to seek less-crowded spots beginning at Topanga State Beach and heading north to the county line.

But for experienced surfers--and surf watchers--Surfrider is the place.

BEST FOR SCUBA DIVING: Point Dume State Beach

A tough one. The north county is hardly a mecca for coastal sea life.

“There’s just not a lot out there,” said Steve Vogel, the education curator at the Cabrillo Marine Aquarium in San Pedro. “It is mostly sandy bottom.”

Divers prefer a rocky sea floor. That is where the vegetation grows, and fish and other interesting sea creatures feed.

At Point Dume, such conditions exist in scattered patches that are identifiable by the beds of kelp that rise to the surface of the water. Similar spots are present at Malibu and Leo Carrillo. Divers need to be choosy.

But Vogel sees one advantage to diving on these beaches.

“It’s a good place to start,” he said, “if only because there are lifeguards.”

BEST FOR TEENS: Beach Park

“Between lifeguard towers 6 and 7--that’s the hip section,” said Allan Peters, 18, of Reseda. “This is where the kids hang out. It’s a very social environment.”

This broad, flat beach allows plenty of room for strolling and volleyball and whatever else teen-agers do at the beach. Fast-food stands supply the basic food groups--burgers, chips and soda. And the waves come in strong enough for bodysurfing.

There’s also a family section, down by tower 5, but that’s dullsville. This is a spot for the young.

“You come here to see people you know,” Peters explained. “It’s like a fashion show where we see who can wear the least clothes and get away with it.”

BEST FOR PRIVACY: Westward and the Northern State Beaches

A short walk south of Zuma lies Westward beach. Out of sight and out of mind, it tends to run empty along a row of cliffs leading to Point Dume. It is tailor-made for romantic strolls, with rarely more than a dozen people dotting the sand.

Even more private are a trio of beaches to the north. El Pescador, La Piedra and El Matador state beaches nestle beneath the bluffs along Pacific Coast Highway. If you can find your way to these spots, you’re not likely to bump into many others.

BEST TIDE POOLS: Leo Carrillo State Beach

“You’ll see things that you don’t see a few miles south,” explained Vogel of the aquarium. “The water is colder and it’s a bit farther from L.A. The coast is starting to look a little like Central California.”

So, at low tide, observant beach-goers can spot sea hares, starfish and a variety of seaweed including the tall, fronded sea palm. Lobsters and octopuses also roam close to this stretch of rocky shore. As a bonus, the park rangers and lifeguards at Leo Carrillo know their marine life.

“They are very informative,” Vogel said.

But tide-pool watching requires patience. On a recent afternoon, clusters of kids on a field trip from the Valley Alternative School in Van Nuys weren’t having much luck.

“All I found was a clam shell,” said one of the students. “And it isn’t even alive.”

BEST FOR BARBECUES: Sycamore Cove

Located in Point Mugu State Park, several miles beyond the Los Angeles County line, this is the only beach close to the Valley that allows barbecuing.

Trees grow along the edge of a sandy stretch, providing shade for a handful of grills and picnic tables. The wooded Sycamore Canyon lies just across the highway.

“You can go for a hike and then come back to the beach and make sandcastles,” said Misty Ysais, who came with her husband and two children.

Sycamore Cove is open from 8 a.m. to sunset, so there is plenty of time for a full day’s activities.

SAFEST FOR KIDS: A Toss-Up

Another tough one. Beaches in the north county face south and west, which means that during the summer months they catch the brunt of seasonal storms that rage south of the Equator.

Malibu, for instance, is likely to have big waves and strong currents from June through August. Dan Blocker State Beach, a few miles north, is relatively calmer but has its bad days as well.

“Every beach will have its times when it’s safe and it’s not so safe,” said Lt. Steve Wood, a Los Angeles County lifeguard. “The point we try to get across is for people to swim near a manned lifeguard tower.”

Wood suggests that beach-goers check with lifeguards before diving into the water. “The lifeguards will be happy to tell you if it’s a safe place to swim,” the lieutenant said.

Surf Beckons

LOCATIONS

* Topanga State Beach, at the intersection of Topanga Canyon Boulevard and the Pacific Coast Highway.

* Malibu Point, 23200 block of Pacific Coast Highway.

* Point Dume State Beach, 29200 block of Cliffside Drive.

* Westward Beach, 7100 block of Westward Beach Road.

* Zuma Beach Park, 30000 block of Pacific Coast Highway.

* Dan Blocker State Beach, 26000 block of Pacific Coast Highway.

* El Matador, La Piedra and El Pescador state beaches, beginning at the 32000 block of Pacific Coast Highway.

* Leo Carrillo State Beach, Pacific Coast Highway at the Ventura County line.

* Sycamore Cove, Pacific Coast Highway at Point Mugu State Park in Ventura County.

HOURS

Vary from beach to beach, as do parking fees. Street parking available at some beaches.