Incidentally, if you want to check tempos on various shanties, listen to the two recordings issued by the Library of Congress' Archive of Folk Song (now the American Folklife Center), "American Sea Songs and Shanties". The LPs are long out of print, but the cassettes may still be available (and let's hope they're reissued on CD soon!) Most of the singers on these field recordings had been sailors or shantymen in the days of sailing ships. Interestingly, most of the songs are sung much more slowly than they're usually sung by revival singers today.

Peace. Paul