June 28, 1981

Nothing will change behind the Islanders' bench next season. Coach Al Arbour will stand there again, rarely smiling, seldom showing emotion and peering through his thick glasses. Arbour, who coached the Islanders to a second straight Stanley Cup championship last season, ended thoughts of retirement yesterday with an announcement that he will return as the Islander coach for the ninth straight season. He will continue to coach for as long as he chooses, evaluating things on a yearly basis, and when he is ready to give up coaching, he will become vice president for player and team development.

LONG ISLAND is going ''live'' on prime-time television Tuesday night, much to the delight of community groups that have been working over the last several years to get more television coverage of the Island by New York City stations. Some 300 Long Islanders from a cross section of the population, including critics of the Long Island Rail Road and the Long Island Lighting Company's Shoreham nuclear plant, will take part in what WNBC-TV describes as a ''live town meeting.'' The program will be broadcast live Tuesday at 8 P.M. from the Roosevelt Hall Theater on the Farmingdale campus of the State University of New York. Onstage, Gabe Pressman will play host to a panel of local experts discussing three key Long Island problems -transportation, pollution and utility rates. The hourlong forum will be rebroadcast next Sunday at 1:30 P.M.

Congress's wish was the Supreme Court's command last week, insofar as coequal branches of Government can defer to one another. Ruling in what it considered more a matter of national defense than equal protection under law, the Court held 6-3 that Congress is within its constitutional rights in limiting draft registration, and presumably the draft itself, to men.

Claudia Ryan, a psychiatric nurse practitioner at Hartford Hospital in Connecticut, is purchasing a $40,000 condominium with the aid of a mortgage program begun this spring by her employers. ''It helps encourage me to stay on the job,'' said Miss Ryan, explaining that on a nurse's salary she would not have qualified for conventional financing on the apartment. The 13 1/2-percent loan is 3 percentage points below the rate she could have received at a local bank and permits her to put down only 10 percent instead of the customary 20 percent downpayment now required by most mortgagelending institutions. Ann Mellor, an English literature and poetry professor at Stanford University in Palo Alto, Calif., has also purchased a home through the mortgage program offered by her employers. Last July, with the aid of C.O.I.N., Stanford's new Co-Investment Second Mortgage Program that provides loans of up to $150,000 at only 5 percent interest, Miss Mellor was able to qualify for a four-bedroom ranch-style house near the campus that sold for $205,000, an average sum for that area. The program provides the 5 percent interest in exchange for a share in the appreciation of the home when it is sold.

Summertime: At seashore resorts, the living is, as the song says, easy. Salt air. Soothing sunshine. Ocean swimming. Warm sands. What could be more benign? Millions of Americans seek these pleasures each summer, yet thousands of them have unhappy vacations because they fail to take the simple precautions needed to keep themselves healthy, even in such healthful environments as the Hamptons, Cape Cod, the Jersey Shore and the Eastern Shore of Maryland. Last summer 7,045 people were treated in the emergency room of Long Island's Southampton Hospital and more than 60 percent of them were suffering complaints that, though relatively minor, were ruining their holidays. Among the diagnoses recorded day after day from June to September in the emergency room's thick black logbook: sunburn, mild food poisoning, headaches, sprained ankles, cut feet, and flesh wounds inflicted by fishhooks that hooked fishermen rather than fish. At times, too, the sting of the jellyfish manifests itself in the emergency room's records. One evening last summer, for example, the doctors at Southampton Hospital examined five sprained ankles, four cases of painful sunburn and two of faces badly swollen by insect bites. ''Nothing particulary severe,'' said Dr. Raoul H. Renaud, the hospital's chief of emergency services. ''We offered sympathy as much as anything else.''