Powerboat Racer Betty Cook Dead at 70 : Champion: The Newport Beach resident was the only woman to win U.S. and world titles in the offshore sport.

Betty Cook, the only woman to win national and world championship titles in offshore powerboat racing, has died of cancer. She was 70.

When Mrs. Cook joined the male-dominated sport in 1970, piloting a high-powered boat over ocean waves at speeds up to 100 m.p.h., she was dismissed as a wealthy and bored housewife trying to while away the hours, she once told a reporter.

“I guess the other drivers thought I was just some rich lady who was going to try something new for excitement,” Mrs. Cook said after winning her first world championship in 1977 at Key West, Fla.

Mrs. Cook proved her critics wrong. She was inducted into the American Powerboat Assn. Hall of Champions in Detroit--the first woman in any class of boat to be honored--and was named England’s “Powerboat Personality of the Year” in 1973 after she won the famed Cowes-Torquay race.

She won 17 races in all, including another world championship in Venice, Italy, in 1979, and three U.S. championship titles, said John Crouse, a chronicler of offshore powerboat racing. The five championships tied the record held by the late Don Aronow, Crouse said.

“She was very courageous and very canny when it comes to racing,” Crouse said. Offshore powerboat racing “is one of the most brutal of all the motor sports . . . and she gave the sport a great push. Even today, very few women (compete), and none has ever reached the height that she did.”

Before she joined the race circuit, Mrs. Cook worked as a researcher at the Massachusetts Institute of Technology and the Stanford Research Institute. She also participated in the presidential campaigns of John F. and Robert Kennedy.

Besides her racing interests, Mrs. Cook was president of Kaama Marine Industries in Newport Beach. She was married to Paul Cook, president of Rachem Corp. They were divorced in 1980. She is survived by two sons, Eugene Ashley and Gavin Cook, two grandchildren and two nieces.

A memorial service for Mrs. Cook, who died Dec. 23 at Hoag Hospital in Newport Beach, will be held in Lake George, N.Y., where she maintained a home. A date has yet to be set.