Kevin Kelly (of Wired Magazine and Whole Earth fame/Coevolution Quarterly/Whole Earth Review fame) posted this link on his blog regarding new-manufacture clones (listeroids) of old Lister Diesels:

http://www.kk.org/cooltools/archives/001011.php



8hp, 850 RPM for less than $1000 it looks like. Should be good for the right sort of boat.