I just discovered Gerr as an author as I've been deep in propeller research. While my library didn't have his well recommended Propeller Handbook, I did just finish reading this:
http://www.amazon.com/Nature-Boats-Insights-Esoterica-Nautically/dp/007024233X
I highly recommend it. The breadth and depth of info in here make me want to keep it on my reference shelf, aboard.
Yes, that's a classic if you're interested in the fundamentals of boat design.
I had the good fortune to edit Dave Gerr's bi-monthly magazine column for several years, until Dave got his position at Westlawn Institute and didn't have time to write any more.
I never met him, but Dave and I always had long, fascinating conversations on the telephone while reviewing the column. He really knows his stuff, and is, at least to his editors, a very nice guy.
--Joe