Born Henry Hunt Searls Jr. novelist and screenwriter Hank Searls, author of the best-selling Overboard, Jaws II (based on the movie), and Sounding, is creator of the New Breed TV series and writer for the 1960's classic television series The Fugitive . His novel Pilgrim Project became Robert Altman's film Countdown. He has lived most of his life on, under, or over the ocean, having been a world-cruising yachtsman, underwater photographer, and Navy flier.
I noted in my journal from 1985 that I'd read the condensed version of "Excellency". A few of the pages on GoodReads suggest a much later publish date for this novel, but it looks like the original full novel was published in 1977 or 1978.