Robert A. Orr, 90, formerly of Chestnut Hill, a retired company chairman and an environmentalist who loved the sea, died of cancer Nov. 29 at Cathedral Village in Roxborough.

Mr. Orr was born in Colorado and grew up in Catalina Island, Calif., where he spent his free time swimming and spear fishing. He invented his own diving mask and created a "re-breather" device before scuba tanks were readily available, said his daughter, Cynthia.

Mr. Orr earned a bachelor's degree from the University of California at Los Angeles, where he was captain of the swim team and a star goalie on the water polo team. He was chosen to participate in the 1940 Olympic Games, which were canceled because of World War II.

During the war, Mr. Orr served in the Coast Guard in New London, Conn., aboard the Danmark, a tall ship used for training. Later, he commanded an LST landing craft in the Pacific.

After his discharge, Mr. Orr earned a master's degree in business administration from Harvard University. He then joined General Electric in Connecticut, where he developed a patent for GE's fan department. In 1963, he moved to Philadelphia to become general manager of a division of Standard Pressed Steel. Two years later, he cofounded A.C. Forr Corp. In 1973, he and his partner formed Anchor Darling Industries, a manufacturer of safety-related valves for commercial nuclear reactors. He retired as company chairman in the late 1970s.

Mr. Orr was a past commander of the Pennsylvania Chapter of the Military Order of Foreign Wars, and was active in the renovation of Fort Mifflin.

He was past president of the board of the Friends of the Library of Eastern University in St. Davids, where he established an award for excellence in research and writing in honor of his son Jonathan, who died of melanoma in 2002.

Mr. Orr was a member of many environmental organizations, his daughter said. In 1998, he was president of the Wilderness Club of Philadelphia when it announced a new mission to promote the preservation of habitats for rare species and to support programs to conserve these species. Under Mr. Orr's direction, the club, which was founded in 1912 as a big game hunting group, supported the Philadelphia Zoo's program to breed endangered species and the effort to return shad to the Schuylkill by removing several dams.

Mr. Orr was an avid sailor and spent years scuba diving off the coast of New Jersey and Florida and in the Caribbean and Europe. He taught his children to swim, scuba dive, sail, ski and play tennis, his daughter said.

Mr. Orr's wife of 53 years, Marjorie Bolton Orr, died in 2002. In 2003, he married Joan Helms Hunter.

In addition to his wife and daughter, he is survived by a son, Duncan, four stepchildren, and 12 grandchildren.

A memorial service was held Saturday at St. Paul's Episcopal Church in Chestnut Hill.

Memorial donations may be made to Stratford Friends School, 5 Llandillo Rd., Havertown, Pa. 19083.