George Haimsohn (1926-2003) who co-wrote the book and lyrics for ''Dames at Sea,'' a musical that has leavened summer stock and college repertories ever since its Off Broadway debut in 1968. He was born in St. Louis and served in the Navy in World War II. He graduated from the University of California at Berkeley, where he had his first poetry published in the student literary journal. A resident of Greenwich Village since 1952, he was a professional photographer known as Plato, designed mobiles and collages and wrote stories, advertisements and limericks as well as gay pornographic fiction under the pen name Alexander Goodman. He also wrote two other musicals, ''Now, Zing!'' and ''Johnny American.'' He wrote and illustrated three other books for college readers, ''The Portable Hamlet,'' ''The Bedside Faust'' and ''Inside Romeo and Juliet,'' published in the 1980's as Madcap Classics by Perigee/Putnam.