Wearied by four days of receptions, meetings, and tours, about 50 delegates to the Atlantic Treaty Association's fourth Annual Assembly boarded destroyers and Coast Guard cutters for a cruise from Newport to the Boston Army Base yesterday.

The 9-hour cruise gave some of the NATO nation representatives their first moments of relaxation in a week. Among their recent activities was a brief tour of Harvard on Tuesday. The delegates were impressed by the size and autonomy of the College, but many were disappointed at not being able to explore the University independently and at leisure.

A member of the British delegation compared the week's touring to that of Americans seeing Europe by bus. Representatives of Turkey felt that the program, although enjoyable, was too lavish, and called such activities as the cruise "too fatiguing for us and too expensive for you."

Members of the delegation who are living in private homes during their stay unanimously praised their Boston hosts. A scheduled month-long tour made possible by the State Department will familiarize one delegate from each nation with other U.S. cities, including Washington, San Francisco, and Chicago.

The Assembly will continue discussion of publicity and support for NATO at an open session at Kresge Auditorium at 3 p.m. today.