In seven years Sea Colony has established itself as a highly identifiable complex of 742 high-rise oceanfront apartments and 58 town houses that spell getaway recreation and relaxation to their owners.

In a decade that witnessed a now-gone surplus of high-rise condo apartment buildings in N. Ocean City to the south and considerable new development in Rehoboth Beach to the north, Sea Colony has become that Washington-oriented oceanfront's largest single complex. And, remarkably, Sea Colony was developed on a site just outside the still somnolent, totally low-rise Bethany Beach summer community that prides itself as a quiet place.

Developed by Sea Colony Inc., a subsidiary of Carl M. Freeman Associates in Montgomery County, Md., Sea Colony now shows eight completed, chocolate-colored high-rise apartment buildings on 2,700 feet of oceanfront. Only two dozen units remain unsold in the eighth building and sales in the final high-rise building (to be completed next spring) are now being planned.

The Sea Colony holding also includes land to the west of the ocean highway, where town houses have been built around an indoor tennis complex. More recreation homes may be built later in Sea Colony West. Altogether, Sea Colony has 17 courts but it is estimated that only 50 per cent of the SC residents and tenants use the courts. Most Sea Colonyites sun and swim in the ocean and also use the five pools (one indoor) that are part of the complex.

The total recreation package includes a new health club in the (largest) Edgewater House building, planned social activities for adults (including disco dancing, bingo and marshmallow roasts) and a camp for youngsters interested in organized games and fun. Newly added is a banquet-luncheon facility. And there's some shopping in the lower level of Edgewater House.

Washington-based owners dominate the Sea Colony scene but increasing numbers of buyers now are coming from Baltimore, Wilmington and varied parts of Pennsylvania, according to Patrick Rhodes Jr., sales manager. He said most of the owners are fiftyish and at least moderately affluent. Most of the apartments now are two-bedroom-two-bath units selling in the $70,000 range.

Among the SC owners are at least half a dozen realty and housing professionals. Washington realtor Earl Farr, who shares ownership of a 1975-vintage two-bedroom with adult members of his family, said that he always enjoys visits to the beach even though he seldom participates in anything more strenuous than walking to the shore-line.

"Our family members share time and we think Sea Colony has been a worthwhile investment," said Farr. "We are particularly satisfied that we took my wife's advice and bought on the third floor so that we are not dependent on the elevators that seem to fascinate the youngsters who flock here in the summer."

W. Donald Calomiris, a property management executive who also has owned a Sea Colony unit several years, said that he shopped both Ocean City and Rehoboth before deciding on Sea Colony. "I was impressed by the layout and have been satisfied by the management and services under the supervision of Bob McGarvey. The monthly condominium fee runs about $100 a month and the recreation association fee about $330 a year. I like the fact that money is being put into a reserve fund for major upkeep in the future," he said.

Neither Farr nor Calomiris rent out their apartments but nearly half of the Sea Colony owners do that. Rents per week "in season" average about $500 a week and the Sea Colony management and other Bethany Beach realtors handle that bookings for a fee-usually about 15 per cent.

While Sea Colony is almost a world within its own just outside the boundary of Bethany Beach in Sussex County, Del., its impact is not lost on the 78-year-old resort community that has only 200 year-around residents. When the Sea Colony plan was unveiled a decade ago, the idea of a high-rise complex was repugnant to most Bethanyites. Now most of them agree with Mayor Vernon Dibeler that Sea Colony has not really changed the community's quiet way of summer recreation and off-season living.

But Dibeler and some other Bethany owner-residents, including Thomas Hooker, are now concerned about Sea Colony plans for another almost-as-high-rise-but-slightly-smaller community to the north.

"We can live with what we have but most of us fear a flurry of high density development between Bethany and the Indian River Inlet. To date, most of the development has been single-family recreation homes in the Bethany tradition," said Hooker. "And we cannot ignore increasing traffic on Rte. 26 into Bethany during the summer.

But Bethany also has a new and expensive sewage treatment system that was built for a future capacity.As a result, users of the system are protesting the high cost of being "hooked up" on one hand while recognizing that only wider use of the system will bring down the costs to area residents, including those in the present Sea Colony.

Although the Freeman group has received a green light from Sussex County to go ahead with Sea Colony North, that plan still is being opposed strongly by Bethesda attorney William S. Green whose summer place is at Tower Shores near the inlet.Preservation of the shoreline and lack of sewers are among reasons for the opposition. But Freeman's group has proposed paying for a hookup to the existing sewer system.

One long-time Bethany Beach developer-builder-realtor said that high density development is restricted within Bethany and that prices for intown and nearby, new single-family cottages and recreation homes on fairly small lots now total about $100,000 at the low and end go as high as $300,000 for some larter places on oceanfront sites,

In a sense, he was supporting the Sea Colony contention that only higher density development can make ocean-related recreation dwellings available to the increasing numbers of moderately affluent persons who want and can afford beach places.

But Sea Colony still stands alone -- high and serene on the oceanfront in the mid-area between Rehoboth and Ocean City. "It has an established resale market and the appeal of a total community not unlike Sea Pines in S. Carolina," said Norman Dreyfuss, executive vice president of the Freeman firm. He added that some construction problems, such as walls leaking during heavy rains, have been solved with new fittings and new exterior aggregate panels on the buildings. "We learned as we went along," he added.

What about the veteran developer who conceived the plan for Sea Colony? Carl Freeman, an executive who swims most mornings at his Montgomery County farm home before going to the office, said simply that Sea Colony has been a financial success and " a project of which we are proud." He added that Sea Colony survived the oceanfront overbuilding of the mid-1970s because of the total planning, landscaping, amenities and management provided on the scene.

Nonetheless, the concern of most Bethanyites -- including even those who own apartments in Sea Colony -- is to maintain much of the status quo of the still-quiet resort community with a small boardwalk and strict rules for beach users. It was almost a little too quiet in July, when the gas crunch kept some weekend vacationers at home. "But we didn't really suffer any cancellations," said realtor-builder Joseph Tansey, whose office is opposite Sea Colony.

Tansey, a retired FBI agent who lives year-around in Bethany West and can't miss seeing Sea Colony every day of his business life, considers the oceanfront complex to be "unique in this area and it looks better every year."