Dear Steven,
 
You might try contacting the Mariner's Museum in Newport News, Virginia.
 They've got an excellent research library with - you guessed it - a focus on
shipping.  Its also a member of Online Computer Library Center (which
suggests that they may be accessible online).  I don't have online info, but
the head librarian's name is Benjamin Trask and his email address is
[log in to unmask]  Perhaps he can fill you in on how to access their resources
- or offer alternatives.
 
Ann