The Hamptons or Martha's Vineyard?

Both have plenty of soft, clean sand and the same short swimming season. The Hamptons is essentially one long Atlantic front from Westhampton to Montauk, with wide beaches such as Cooper's and Main Beach. It has real surf, Ditch Plains for surfers, and calm bay beaches on Peconic and Gardiners Bays for small children.

Martha's Vineyard turns the balance around. Its everyday swimming is the calm, shallow water along State Beach on Nantucket Sound, with south-shore surf at Katama and the clay cliffs of Aquinnah for scenery. Both keep some of their best sand for locals, the Hamptons through parking permits and the Vineyard through up-island beaches reserved for residents and renters.

The Hamptons has more to eat across a wider range. There are polished seasonal restaurants in four or five village centres, gourmet delis for the beach picnic, roadside stands selling corn and strawberries, and wineries on the South and North Forks. What's missing is anything casual or cheap in between.

The Vineyard keeps things simpler. Its high point is steamed lobster eaten on the docks at Menemsha, along with chowder, fried clams and pond oysters, plus the farmers' market in West Tisbury. The restaurant scene in Edgartown, Oak Bluffs and Vineyard Haven is small, and limited alcohol licensing up-island means you often bring your own bottle.

Neither is a place to come for sights, and the difference between them is in kind. The Hamptons' strength is art: Pollock's studio in Springs, the Parrish Art Museum and Guild Hall. Add Sag Harbor's whaling streets and the saltbox houses and windmills by the village greens, and it makes an afternoon or two between beach days.

The Vineyard's heritage is in its townscapes and communities, and it takes a little longer, two or three days of looking around. Look for the painted gingerbread cottages of Oak Bluffs' camp-meeting ground, Edgartown's captains' houses, the Wampanoag land at Aquinnah, and a heritage trail tracing the island's long history as a summer resort for African American families.

The Hamptons has far more after dark, at least from late June to Labor Day. Montauk's bars stay loud late with a young beach crowd, and Southampton and Bridgehampton have clubs with door policies, though the famous parties happen behind private gates.

On the Vineyard, a night out means a few bars on Circuit Avenue or along Edgartown harbour, with a crowd of visitors and seasonal staff that thins out early. In both places a late night means a taxi on dark roads, and out of season there is little at all.

Both are gentle and low-lying, good for easy outdoor days rather than adventure, and they differ mainly in emphasis. The Hamptons centres on the water and the far east end. There are bluff trails at Montauk Point and the Walking Dunes, a serious sport-fishing harbour, surf at Ditch Plains and seals hauling out in winter.

The Vineyard has more protected land to wander through. Moors, stone walls and trails at Cedar Tree Neck lead down to the shore, Felix Neck has ospreys, and Cape Poge on Chappaquiddick is a wild barrier beach. Its bike paths through the state forest are the classic way to see the island.

The choice is about even, and in both places the best outings go by water. From the Hamptons, small ferries via Shelter Island reach the North Fork's tasting rooms and the working harbour at Greenport, and in summer a boat from Montauk goes to Block Island. New York is a place to start or end the trip, not a day out.

From the Vineyard, summer ferries from Oak Bluffs reach Nantucket's cobbled whaling town and New Bedford's historic whaling district with its museum. The year-round boats to Woods Hole open up Falmouth and Sandwich. Many of these crossings stop outside the warmer months.

The two are equally good for families, and both work best as a rented house and a beach routine. The Hamptons has more to do on a dull day, with pick-your-own fields, the lighthouse climb and the Long Island Aquarium in Riverhead, though each outing means time in slow traffic.

The Vineyard makes up for that with ease. Children can cycle between Oak Bluffs and Edgartown, ride the antique Flying Horses Carousel and go crabbing off the docks. With no aquarium or rainy-day museum, though, a wet week drags, and getting everyone and the luggage onto the ferry takes planning.

In the Hamptons you need a car. The villages line a single highway that slows to a crawl on summer weekends, so 30km can take more than an hour. Taxis are scarce, and many beaches need parking permits. Its one advantage is arrival: trains and coaches come straight from New York with no ferry to book.

Martha's Vineyard is much easier to manage without a car, and many visitors leave theirs on the mainland. The down-island towns are compact and walkable, with paved bike paths linking them, and the island buses run as far as Aquinnah. In summer the traffic trouble is mostly on the winding up-island roads. Outside the season the buses run less often and a car becomes more useful.

The Hamptons is a real shopping destination in summer. Main Street and Newtown Lane in East Hampton and Jobs Lane in Southampton carry outposts of fashion labels, cashmere and jewellers. The antiques and interiors dealers around Bridgehampton and Water Mill are the local speciality.

The Vineyard's shopping is a pleasant way to pass an afternoon, not a reason to come. You'll find preppy boutiques and galleries in Edgartown, bookshops in Vineyard Haven, and pottery and paintings at the Chilmark flea market and artisan fairs. There is no luxury end, and in both places many shops close after the season.

Both are very expensive in July and August, with lodging often rented only by the week and little cheap food anywhere. In the Hamptons, rooms cost more than in New York and even a deli sandwich is priced for the wealthy. Staying further west or on the North Fork is the usual way to save.

On the Vineyard, the ferry adds to the bill, especially with a car, but the buses and a bike keep daily costs down once you're there. In both places, June, September and farm-stand picnics make the biggest difference.

The Hamptons has the better summer programme for a rural resort. Guild Hall and Bay Street Theater stage plays and concerts, the Westhampton Beach venue brings in touring acts, the Bridgehampton Chamber Music Festival fills churches with classical music, and the film festival carries the season into autumn.

The Vineyard's programme is smaller and more local. There are concerts and sing-alongs under the open-air Tabernacle in Oak Bluffs, a small playhouse in Vineyard Haven and bands in a few bars, but no festival with the reach of the Hamptons' best.

In both places rest comes from the seaside pace rather than any spa tradition, and both are calmest in June and September. The Hamptons has the stronger spa side, with resort spas and seawater pools in Montauk and Southampton and yoga in every village. Its midsummer weekends, though, can feel more like a social whirl than a rest.

The Vineyard has only a handful of inn spas. What it offers instead is up-island: quiet roads and long evenings around West Tisbury, Chilmark and Aquinnah, well away from the summer crowds in Edgartown and Oak Bluffs.