We have a stash of spare alternators. The boat's previous owner seemed to buy anything he found as a good deal. They're all new ones. Because I'm investigating how to hook up one of our existing alternators to our prop shaft for use as a prop shaft generator, I recently ran across some information that this couple used a prop shaft generator and managed to run some hefty electric needs (electric autopilot and refrigeration included) with the electricity generated from it during their world travels.
Between 1948 and 1950, the Crowes spent two years seriously circumnavigation the globe. They won the prestigious CCA Blue Water Medal in 1951, citation:
1950 Lang Syne WILLIAM P. & PHYLLIS CROWE U.S.A. From Honolulu around the Cape to New England, from Easter Sunday, 1948, to the spring of 1950. After the award the 39-foot oa., home-built Block Island type double-ended schooner completed her circumnavigation to Hawaii.
Here's a nice newspaper article about their travels--
Reading Eagle - Google News Archive Search