ONE OF THE REASONS for travel is to see how other people live. This may even be the reason somebody once mutted that travel is broadening. Few of us learn anything lounging on the porch of a resort hotel watching the tennis.

If you believe this, Tangier Island is for you. But don't say I didn't warn you if you require all the comforts of home when you're away.

Tangier, an isolated community in the middle of southern Chesapeake Bay, has lately been touted as a tourist attraction. Don't you believe it. Tangier Island is a trip into another culture, another century, and you must go with this in mind. If you leave the escorted group tours that dock daily and the visitors who plod up King Street to eat at the Chesapeake House, you will be rewarded with a glimpse into what life's like on a windswept island largely removed from what occurs on the mainland.

To see Tangier you should stay overnight, which admittedy is hard to do. The Chesapeake House, run by Hilda Crocker's daughters, has nine rooms usually booked way ahead. Euna Dise, a widow who lives a block or two down King Street, rents out her two spare bedrooms, and that's about it. Only 925 people live on this island, 2 1/2 miles long and less than one mile wide, and they make their living from the sea. To most of them, the tourists are a brief afternoon visitation in the summer, clogging the narrow streets.

But stay awhile after the Stephen Thomas, a new 75-foot aluminum cruise ship, collects her passengers and returns to Crisfield, Md., and the ferryboat steams off in the other direction for Reedville, Va. This tight little island is far more interesting than the tour boat passengers know. Sit a spell at the harbor dock, walk along the unpaved roads, knock at the doors of the houses where signs offer crab cakes and fresh bread for sale, and you'll meet the people who live on Tangier.

The island is so isolated by its position 15 miles from the Maryland shore and 20 from Virginia that the natives still speak in the Elizabethan cockney accents of the men who first settled here in 1686. Nearly everybody is called Parks, a full third of the islanders, and the rest are mostly named Thomas, Crockett or Pruitt. Two-thirds of the high school class of Tangier marry and settle down on the island every year, and the same family names get perpetuated.

Visit Tangier and you'll discover people live very well without some of the things we take for granted. Only two or three automobiles exist on the island, and though television has come to Tangier, repairs are a periodic thing, so a long list greets the repairman when he arrives to check his calls at the general store. There is no doctor and, until recently, the islanders buried their dead in their own gardens, erecting wonderful headstones with flowery inscriptions only a few yards from where the departed spend the bulk of their lives. "Gone to be an angel," says one banked by marigolds. "A friend to everyone," says one headstone off King Street.

King Street, the only paved road, is about 10 feet wide, bordered by chain link fence and plagued these days by a proliferation of motor scooters. The tourists, trudging up the street from the excursion boat that docks daily at 1:45 p.m., plunge into a maelstrom of bicycles, motorcycles, pedestrian traffic, dogs and children that, considering the size of the street, rivals the traffic of Rome. The social event of the day is the opening of the post office, and people gather on the steps to await the mail, admiring babies, patting dogs, passing remarks about the weather and remembering the halcyon days of 1973 when National Geogrphic arrived with its photographers and people got their pictures in a magazine. When the post office opens, everybody surges in with enthusiasm because the Sears Roebuck catalogues are due.

The boat passengers know about the meals served at the Chesapeake House, and they bee-line there for a sample. On a busy summer weekend afternoon, Chesapeake House, an old clapboard structure still dressed up in its Bicentennial red, white and blue, may serve 700 people, all of whom sit at long tables to consume a feast to make the mind reel. Crab cakes, clam fritters, corn pudding, pickled beets, ham, homemade applesauce, hashed brown potatoes, fresh rolls, pound cake, iced tea -- that's only what I remember -- $7.50. It's all handed round by the quests themselves, a great icebreaker and friendship-making aid.

Stuffed with such a meal, a sit-down tour of the island is a little golf cart piloted by enterprising women of the island appeals to most of the guests, who fork over $1 for a chance to view it all without further effort. The length of King Street and a swing by West Ridge, where the houses face the winds off the open water of the continent's largest estuary, and it's cover. At 4:15, the whistle of the Steven Thomas calls the last stragglers to its bosom, and once more Tangier belongs to the natives.

Determined to do it with a bit more depth, my daughter and I began to try to book a room the Wednesday before the weekend. The Chesapeake House was booked solid but, at the suggestion of one of its waitresses, we made a deal with Euna Dise, who agreed to put us up for the night in one of her spare bedrooms. Mrs. Dise offers no meals, but you can take them at the Chesapeake House.

You can reach Tangier Island from either Maryland or Virigina, the last being closer to Washington. But since we were eager to visit the Carvel Hall factory outlet just a mile north of Crisfield, and to take a look at this old fishing village, partly built on oyster shells, we chose Maryland in spite of extra miles.

We learned to our sorrow that the brochures for Crisfield--"Gaetway to Tangier"--greatly underestimate the travel time from Washington on a summer weekend. Starting at 8 a.m. Saturday--the earliest we could get the dog in the kennel--we hit the beach-bound traffic with a two-mile backup at the Bay Bridge and a second horrendous traffic jam at the Choptank River two-lane bridge. The approach to this bridge is a terrible free-for-all, since some drivers do not merge right when the signs order it and expect to be let in later at the front of the line.

We arrived hot and barely in time to catch the Steven Thomas as she steamed out of the pretty little harbor. Carvel Hall knives, which gained a national reputation from the original oyster shucking knives, were out of the question and the outlet is closed on Sunday. The trip with beach traffic is more like 4 1/2 hours.

Disembarking from the boat, we carried our overnight bags to Mrs. Dise's little white house set off from the street by six feet of yard and a chain link fence. Mrs. Dise, hair in pink rollers in anticipation of Sunday church, led us to our bedroom, which waslarge and clean, cooled only by a large fan and overlooking one of Tangier's ubiquitous graveyards. We shared the bath downstairs with the occupants of the other room and with Mrs. Dise.

Tangier Island is essentially treeless, despite a small number of flowering fruit trees, and it gets very hot in summer. Nevertheless, we set off to explore the unpaved roads, declining Mrs. Dise's offer of bicycle rental in favor of aimless strolling. It didn't take us very long to realize we had undertaken quite a safari and, exhausted, we knocked at the door of one of the houses on West Ridge which advertised crab cakes and fresh rolls.

The mistress of the house introduced herself as Adeline Parks and invited us in as if we were old friends. "I don't feel anything happens by chance," she said as if she were expecting us and, clearing a space for us at her oak kitchen table, put before us warm rolls from her oven and iced tea. The money we paid would go, she said, toward her dream home for elderly island people, who now must leave Tangier when they can no longer care for themselves.

The islanders are deeply religious and live their religion all week long, a legacy from the feisty parson of the island, Joshua Thomas, who led famous Methodist camp meetings here. The young man seated next to me at the Chesapeake House wore a T-shirt inscribed simply "Jesus."

The Bible and its teachings may account for the fact that there seems to be no crime on Tangier. Mrs. Dise's door stood open to the street all night long, though her parakeet was the only "watch dog." The guide books on sale on King Street lay unattended across from the Chesapeake House, beside a growing pile of dollar bills. No one locks his bicycle on Tangier Island.

Everybody keeps early hours, since the boats go out at 3 or 4 in the morning and return about noon. Supper is at five o'clock at the Chesapeake House and that leaves you a long evening. We decided to walk down to the harbor to make acquaintance with some of the watermen and, stopping to admire the Joansy, a round stern boat belonging to Sonny Parks, we introduced ourselves to ask a few questions.

Sonny hopes his son won't be a crabber. Too hard a life. A Marine, maybe. Now there's a good life. Sonny was in the Vietnam War, but he came back to Tangier. Of course a crabber's independent, and that counts for something. He shrugged. Fuel is high and the competition's getting worse and worse.

Sonny gets $5 a dozen for the soft shell crabs that bring such fancy prices in Washington and New York. Big beautiful "pilers," as the Tangier watermen call them, peel their shells in long troughs along the shore at the yacht basin, where the sailboats anchor. Ninety-five percent of the country's soft shell crabs come from the Bay waters.

"What would this 'un bring in New Yawk?" inquires a fisherman, holding up a huge crab spilling over both sides of his big hand.

You don't get crab for breakfast at the Chesapeake House, but you do get all the ham and bacon you can eat, eggs, fresh rolls, hashed brown potatoes, jam and coffee for $3.50. And afterward, if you don't want to return on the afternoon cruise boat, you have to figure out how to get back across the water. You make your own arrangements, and ours were by way of a small motor boat leaving about 9 a.m.

One of the things it is well to know when you get outside the beaten tourist track is that things are not always spelled out for strangers. City folk very often lag behind the full drift of the situation, and it is best to keep this in mind. If you doubt this, sit beside me and tune in on my conversation with a middle-aged couple on the harbor dock.

"You goin' over to Crisfield?" she asks me.

I am, I say. In that motorboat over there, now being gassed up. Perhaps we are to be fellow passengers.

She doesn't answer, moving her gaze to the sky above my head. Having taken a reading, she folds her arms and turns to her companion.

"We all go in that boat, we get wet," she announces.

Get wet? Did she mean from spray? A cold feeling in the pit of my stomach tells me she did not.

"She's got a new motor," mutters the man.

But the decision was obviously not his.

"Go git Art," she commands, "and tell him we need him to take us over to Crisfield."

But the first boat, I cry in panic, what was the matter with that? Wasn't it safe? Why weren't they going on it?

They squint at the sky again and allow as how there's a "far wind" and likely we'd be all right.

Likely? The palms of my hands were getting sweaty. I got up and went over to the man who was busy filling the boat with gas. Was this boat quite safe? And, by the way, how much was he charging me to take us over?

He straightened up and took his own look at the sky.

"Depends on what kind of trip it is," he said and bent to his nozzle again.

That was when I knew we weren't going. I walked up the road and routed Sonny out of his house to take us across on the Joansy. I had to pay him $35, and you may strike a better bargain should you want to leave at your own convenience. All I can say is, it was a wonderful trip. We sat on opended crab baskets, shouted at each other over the motor, sighted a land shark dipping in and out of the water, saw the only buoy I ever expect to see standing in for a state line marker. En route Sonny treated us to a beer.

Crisfield bills itself as the crab capital of the world and it may well be. Its past has been tied up with that fluctuating market from the days when the railroad first reached this little port. On Labor Day weekend Crisfield is host to the famous Hard Crab Derby, to which even the governor of Hawaii sent an entry (though it was disqualified on the grounds that it was not edible). But of a Sunday morning, it is just a fishing town sleeping in the sun. Its harbor is picturesque, and a nice restaurant, the Captain's Galley, sits right on the waterfront and apparently serves crab every way it is possible to serve crab.

At the Chesapeake House we met a couple from Silver Spring who had chosen to come to Tangier from the Virginia side. To do this, since the ferry leaves at a rather inconvenient 10 a.m., they had stayed overnight at the Washington and Lee Motel, south of Montrose, Va., 21 miles from Reedville, where the ferry departs. Their drive was three hours from the Beltway. Their room at the Chesapeake House cost $44, modified American plan.

Mrs. Dise, pink curlers out of her hair and studying a well-marked Bible, handed us a bill for $6 per person. I would not want her to know that I had to pay $7 to board my dog overnight.