Ruth Gruber is one of the hardest working people in show business. The author of the recently updated "Exodus 1947" and a forthcoming account of Jewish refugees rescued in 1944 has covered 23 cities in the past two months as part of a publicity tour.

Not bad for someone who's been 39 for "almost 50 years."

"I like Jack Benny's take on things," Gruber, 86, said during a phone interview last week from her home in New York.

But the ageless writer has clocked many miles covering some of the most seminal events in Jewish history, including the legendary 1947 voyage of the Exodus, where she was the only journalist on board. Three years earlier, she was also the only journalist present when 1,000 Jews traveled by boat through Nazi-infested waters to escape the Holocaust. The boat reached safe port in Oswego, N.Y., on the shores of Lake Ontario.

Gruber's latest book, "Haven: The Dramatic Story of 1,000 World War II Refugees and How They Came to America," isn't scheduled for publication by Time Books until April. But it has already been turned into a musical, which debuts on Sunday in Los Angeles.

"I'll be there, just to show people I'm still kicking," said Gruber, who will be in San Francisco Monday to speak at a Hadassah luncheon.

The writer of the musical, Jerry Coopersmith, has impeccable credentials. Like Gruber, he's an East Coast Jew. And he's not unfamiliar with drama. Coopersmith was one of the chief writers for "Hawaii Five-O."

"Patch me into McGarrett," Coopersmith said Tuesday during a phone interview from New York. "That's my trademark line."

Coopersmith first met Gruber when she audited a writing course he taught several years ago. Gruber told him she had a little writing experience. He asked to see her work.

"I was just blown away by 'Haven,'" Coopersmith recalled. "It's such a story of epic proportions that it just cried out to be cast as a musical. There are some works that are too overwhelming to be expressed in words, and this is one of them."

Coopersmith added some elements to the musical not present in the book, including romantic liaisons involving the author herself. "'Haven' really is about romance," Coopersmith said. "Romance for a new life and opportunities, and romance between the passengers.

"I don't see how you can avoid that angle," Coopersmith added. "In such tight quarters, with so much at stake, people are going to turn to each other for love and support."

Gruber was just fine with the changes. And she freely admits that she wasn't immune to all the romantic opportunities. Although she does add that she maintained her "journalistic objectivity " during the ship's travels.

Gruber believes that a musical version of "Haven" won't translate into a nautical version of "Fiddler on the Roof." Even with some dramatic liberties, she believes the musical stays true to the book's roots. "I think it's a fantastic way to look at 'Haven,'" Gruber said. "The musical really captures all the passion, romance and fear of those times."

"Haven" has also inspired a television movie, scheduled to be aired next year.

In talking about the book and its adaptations, Gruber said there were 450,000 Nazis, captured as prisoners-of-war by the United States, who were brought to America. She noted the irony of them debarking at the same time the refugee ships were docking on U.S. shores.

"The Nazi POWs received work furloughs, while the refugees weren't allowed to leave the Army base they were housed at," said Gruber, a former war correspondent who has published 14 books. "Some of those Nazis eventually got full-time work, married and became American citizens."

Gruber, who's looking forward to being on hand for the Los Angeles premiere, said she hopes the musical is another way of "lifting the curtains on a dark chapter of history." After all, she's no stranger to heavy lifting.

One doesn't stay 39 for 50 years just by standing still.