OLD A.H.G. MEARS used to spend sunny afternoons on the porch of his hotel, sitting in a rocking chair and watching that small part of the world that goes by in the village of Wachapreague on Virginia's Eastern Shore.

Young Zadoc Randolph Lewis III, already calloused by the proud but grinding life of a waterman's son, saw Mr. Mears as the very symbol of success.

"The hotel was the grandest thing on the Shore when I was growing up, and for my money it still is," Lewis said as he showed a visitor around the 75-year-old masterpiece of Victorian carpentry.

"Rich and famous sportsmen came here from all over the country for the deep-sea fishing, and the ladies would dress for dinner. I thought that a man who owned such a place was just sitting on top of the world."

Like most young men of Wachapreague, Lewis crewed on the fishing boats, whose clients might be newmoney arrogant one day and thunder-bolt-generous the next - more than one of them underwrote college educations for boys who had worked hard at helping the men play.

And, also like all young men of the Shore, when high school was over the future promised nothing but the toil that makes a waterman old at 40, and Lewis moved away. Wachapreague's population once almost reached 500, but it faltered and it's about 100 less than that now.

"Around here, if you don't start out with money you're not likely to wind up with much," Lewis said. "All the time I was growing up I was just counting the days until I could get away. But after I'd finished a hitch in the Marines and went into business as a painting contractor, I started wishing I could come back here, just to be able to get up in the morning and look out over the marsh.

"You know, there are six seasons in the cycle of the marsh, and all are more beautiful than anything else in the world, at least for something you look at every day."

While Lewis was away the Wachapreague hotel fell on hard times. The corporate pace being what it is these days, your modern sportsmen of affluence no longer takes July off to chase billfish. He flies in Friday night, complains if the skipper doesn't hook him up with a monster marlin by noon on Saturday, and bugs off Sunday afternoon, looking anxiously at his watch.

Worse yer, his wife comes too, even the kids, and if she doesn't like to fish and isn't a birder, doesn't give a damn about the splendors of a marsh that changes in texture and tone from hour to hour, time will hang heavy upon her. The kids will go nuts and take her with them.

Mears and two generations of his descendants tried to cope with the changing times with mixed success. People no longer were willing to share bathrooms at the end of the hall, so baths were added to each room; unfortunately they jut out into the wide verandans that encircle two floors of the building. A swimming pool was added.

The Wachapreague's magnificent proportions overcame the indignity, but then the interior was "remodeled" is motel ticky-tacky: carpet covered the fine oak flooring, vinyl sheathing hid the wainscoting and perforated ceiling tile was pasted over the inch-thick plaster.

It all did away with much of the charm without solving the basic problem: while the waters off Wachapreague remained fertile as ever, many sportsmen no longer had the time and the newly sporting middle class didn't have the inclination (they travel in campers now, of course, and the village fathers enacted an ordinance requiring campers and trailers to get off the streets by sundown).

The classic American answer to the question of what to do with such a faded, old-fashioned hostelry would be to call in the wreckers or take more insurance and have a fire.

It isn't going to happen. Lewis, 41, has come home again, and this month he bought the Wachapreague hotel, lock, stock and marina, committing $520,000 and, he hopes, the rest of his life, to the proposition that he can revive it.

"My brother Jim (an insurance man who also said the hell with the city and came home to Wachapreague) and I leased the marina operation for a couple of years, and what I have seen convinces me that we can make this place go, if we can restore the atmosphere that make it so attractive in the first place."

"We" no longer includes his brother, who has opened Big Jim's restaurant in nearby Melfa, but it embraces three generations of Lewises - his father, Z.R. Lewis Jr., his son Randy (not the IV), 17, and daughters Susie, 13, and Selina, 8.

Nancy Lewis, whose misgiving if any about the radical change in the family's lifestyle are well concealed by an air of enthusiasm, brings the whole brood down from Baltimore County every weekend to work on readying the hotel for the coming season. The children bring friends, making the work parties as much party as work. The commuting will end as soon as school is out.

"It's going to take a few years to really restore the place," Lewis said.

"For one thing there is so much to do. For another, things don't get done around here the way they do in a city."

He smiled as he inspected a bentwood dining room chair in sore need of recaning. "You hire somebody around here to do something and it gets done, eventually, but you don't say, 'I want this by Thursday.' People here move at their own pace and you have to more with them.

"I started to get a little tense about that a week or two ago when we were trying to fix the water pipes - a hundred water pipes - that burst during the big freeze. Then I reminded myself that the reason I came back here is because the Shore is different.

"I've got no reason to hurry. Our family has been around here a long time and there's plenty of time to do everything."

Lewises have been on the shore since 1632, when the line was founded by John and Lucretia Lewis, and there are cousins beyond numbering throughout Accomack and Northampton counties.

Wachapreague itself was an Indian village, whose peaceful inhabitants helped the white settlers established themselves on the peninsula and were rewarded with smallpox. Nothing remains of them but the mellifluous names they gave to the creeks and bays: Machipongo, Onancock, Pungoteague, Chesconessex, Assawoman, Nassawodox, Metomkin, Chincoteague.

Though it was built in a matter of months in 1902, the all-wood hotel remains sound. The Wachapreague survived the hurricane of 1933, when a storm tide covered Parramore Island and waves swept over five miles of marsh to break on the steps of the hotel. It swept boats up into the town and knocked down great trees on the lawn, but the hotel lost only a little of its ornate woodwork.

So solid is it that a visitor, wakened by the brilliant and unaccustomed light of the stars, could not hear the building creak nor feel it move in a 30-knot gale, which is more than you can say for the masonry Holiday Inn out on the highway.

"Oh, there's not another place like it in the world," Lewis exulted as he began another long day of fixing a thousand things. "Say, did you see the deer out on the marsh this morning?